Lung Lau Yin, The Administratrix of the Estate of Chan Kin Shing, Deceased and Another v. So Kwan Mo and Others

HCPI 404/2014

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

PERSONAL INJURIES ACTION NO 404 OF 2014

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Date of Hearing:  24 November 2016

Date of 1^st and 2^nd Plaintiff’s submissions:  24 November 2016 and 12 January 2017

Date of 1^st and 2^nd Defendants’ submissions:  23 November 2016 and 11 January 2017

Date of Handing Down Decision :  23 February 2017

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D E C I S I O N

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1.This is a personal injury claim concerning a fatal road traffic accident.  There was a collision between a motor vehicle (driven by the 1^st defendant, Mr. So) and a bicycle rider and the rider died from his injuries.

BACKGROUND

2.In DCCC1233 of 2011, District Judge Yau found that the Mr. So was driving at 30‑40km per hour and did not find, beyond reasonable doubt, that Mr. So had failed to drive at a standard expected of a qualified and careful driver and dismissed the charge of “causing death by dangerous driving”.

3.Despite this, in the current claim, the plaintiffs continue to dispute over the speed that the motor vehicle was travelling (alleging that Mr. So was driving “too fast in the circumstances when approaching the junction” see paragraph 11(vi) of the Statement of Claim) and has made an application to adduce an expert report on liability from Mr. Lo Kok Keung, an “automotive engineering expert” (as claimed by the plaintiff) dated 26 October 2016.  This is opposed by the defendant.

4.At the hearing on 24 November 2016, I have expressed various concerns with Mr. Lo’s opinion.  I have directed Mr. Lo to provide a supplemental report to address such concerns and for the parties to make a further round of submissions on the supplemental report, and for the matter to be dealt with on paper.

MATTERS IN DISPUTE

5.The legal principle for the court to allow leave to adduce expert evidence is trite: the court needs to be satisfied that such evidence is “necessary”, “relevant” and of “probative value”.

6.Mr. Lo, a chartered mechanical and marine engineer, claimed that he could determine the speed of the relevant vehicle using the “Principle of Conservation of Energy” to set an equation with only the following data: the weight of the deceased, the weight of the bicycle, the distance between the collision spot and the spot where the vehicle finally stopped, the distance between the collision spot and the spot where the deceased / his bicycle landed, the height from the ground to the impact point of the windscreen of the vehicle and the weight of the vehicle.

7.The methodology used by Mr. Lo (which I will refer to as “the Equation”) was explained in his report dated 26 October 2016.

8.There is no need to go into great details but I can summarise “the Equation” as follows:

i) Mr. Lo estimated the “throwing speed of the deceased after being hit by the car” by using a “Motion of Projectile Method” formula using data from what a witness said was the distance the deceased was thrown (assuming that there was no margin of error in the witness’ evidence), and adopting “the centre point of the windscreen of the vehicle as the impact point” and assuming that to be 1.4m from the ground (again without catering for any margin of error in measurement).

ii) After obtaining this “throwing speed”, Mr. Lo put this into a formula which stated:-

“Kinetic Energy of the car = braking energy of the car + deceased energy + deformed energy (including car, bicycle and sound).”

iii) The data he put into the formula was from various further assumptions made: assuming what a witness said he heard as the length of honking time was without margin of error (actually the witness said “2‑3 seconds” but Mr. Lo, for no explanation, decided to take 2 seconds as his input data) and assuming that the driver braked the car and honked at the same time (but there was no evidence on when Mr. So applied the brake: whether he did it before, at the same time or after the honking, if he honked at all); using unexplained data (e.g. the value of the “coefficient of friction of tire”, “coefficient of friction of deceased” and that “deformed energy” was “0.1%” of the total kinetic energy consumed by the damages to the bicycle, car and sound (what about the “deformed energy” which caused the physical injuries on the deceased’s body?) etc..)

iv) He then concluded that the vehicle was travelling at 77‑94 km/h.

9.Right from the beginning, I have expressed my concern with “the Equation”.

Probative value of a “theory”

10.Any subject worthy of being called “science” does not advance by an individual claiming that his “armchair theory” (or, using a more scientific term, “unproven hypothesis”) is a usable “scientific principle” without proper evaluation and publication in peer‑review journals.  This would allow such a claim to be criticised, repeatedly performed and tested by his peers in the same specialty area, who might publish further papers to support or discredit the claim.

11.If such a “hypothesis” was properly evaluated by experts around the world and found to be reasonably accurate, reliable, consistent and was of predictive value etc., the “hypothesis” might become a “scientific principle” accepted by most experts in the field, and might likely be published in textbooks and taught in properly accredited courses on the subject around the world.

12.Until then, any “armchair theory” thought up by an individual may have little or no probative value in court.

13.The court is not the forum for an expert, self‑proclaimed or otherwise, to champion his own “armchair theory” (or, worst, opposing experts arguing competing “pet theories”) before the judge, whose job is not to be a critic to evaluate the scientific soundness of such a claim.  A judge, not being a peer expert on the subject, is not qualified to do so and should not be doing so in the first place for fear of venturing into the territory of “giving expert opinion from the bench”.

14.As such, I have directed that Mr. Lo should address the court, amongst others, as to whether “the Equation” was supported by publications in peer‑review journals or textbooks etc. on the subject of road traffic accident reconstruction.

15.It would be reasonable to assume that a road traffic accident involving a motor vehicle and a bicycle could not be such a rare occurrence and if there was any reasonably accurate and consistent methodology to calculate vehicle collision speed, someone would have proposed, evaluated and published it.

16.For example, as far as I know, the measurement of skid marks (if such are found at the accident scene) is an accepted methodology in the field to measure vehicle speed and such a methodology is widely published.

17.In other words, it is for Mr. Lo to satisfy this court that “the Equation” is well‑accepted by reasonable experts in this area, and not an “armchair theory” that he thought up which was untested and unevaluated in real life situations, and never published in any peer‑review journals or textbooks, or taught in any properly accredited courses on the subject around the world.

Dispute in data collection

18.In the supplemental report, I note that Mr. Lo has explained that the “coefficient of friction of the deceased” of 0.6 was “usually adopted by experts when estimating the energy of a person gliding along a hard surface” and that he has “done a test by gliding an object wrapped with…fabric on a road surface” etc.

19.As a passing comment, I wonder if that test was published in any recognised scientific journal or it was just a test Mr. Lo has conducted himself under conditions that only he himself knew.

20.Mr. Lo also explained why he took 2 seconds as the honking time (thus assumed to be braking time) because:-

“…this yields a pre-accident speed of 85.4km.h. If a longer duration were to be applied, this would result in a higher pre‑collision velocity and hence not consistent with the defence case of his travelling at way below 70km/h.”

21.As such, Mr. Lo has already admitted that he has “cherry‑picked” the evidence so it appeared more consistent with one party’s claim.

22.In law, it is not the role of an expert to decide on the facts.

23.In science, by selecting the figures to be consistent with a known conclusion, Mr. Lo has committed, as I understand, the fallacy of “leading the evidence” or “confirmation bias”.

24.In other words, there may be many reasons why inputting such data may create erroneous conclusions: maybe the data (i.e. the witness’s estimation of time) is not reliable enough, or that many other data are unreliable or wrong, or that “the Equation” itself is flawed etc..  But “massaging” the data towards a more reasonable conclusion meant that Mr. Lo has already disregarded these other reasons: he has simply manipulated the data so that it supported (and thus “confirmed”) a preconceived conclusion.

25.Nevertheless, my observations of possible defects in his “data collection” process and the methodology are no more than passing comments.

26.The plaintiffs’ counsel, Mr. Tommy Lo, has argued that such disputes over data employed should be placed before the trial judge for determination.

27.I do not agree.

28.As I explained above, it is not the role of a judge to be a scientific critic.  It is for the expert to show the court that any data collection was done in accordance with well‑established “scientific principles” (e.g. measurement of the length of the skid mark in the methodology I mentioned as an example in paragraph 16 above).  For example, if “honking time” is scientifically proven to be a reliable guide to “braking time” because studies show that this is how a normal driver behaves, then the court need to see such in peer‑review publications.

Is “the Equation” established?

29.Nevertheless, even if Mr. Lo can provide entirely satisfactory explanations as to how he came up with his data, it is not as important as showing that “the Equation” (which he put the data into) is an established “scientific principle” accepted by most reasonable experts in the field.  If “the Equation” is not established, it is a complete waste of time to argue what data should be put into “the Equation”.

30.In fact, Mr. Lo has only exhibited textbooks showing the simple formula of kinetic energy and potential energy and how one is converted to another by a motor vehicle rolling downhill etc..  Such basic scientific principles are well‑established but are entirely irrelevant to the concern of the court.  Anyone can think of any number of “armchair theories” based upon simple basic scientific principles, but unless such hypotheses are properly tested (e.g. real life experiments and reconstructions etc.) and the methodologies published and critically reviewed by peer experts, they will remain as “armchair theories”.

CONCLUSION

31.Mr. Lo has failed to show this court one single reference to “the Equation” published anywhere in any peer‑review research papers, textbooks or teaching materials used in properly accredited courses on the subject of accident reconstruction.

32.I therefore see no evidence that “the Equation” is an established “scientific principle” well-accepted by reasonable experts in the area.  Mr. Lo’s opinion is therefore no more than an “armchair theory” which is of no probative value to the court and is not necessary or relevant.

ORDER

33.I would therefore dismiss the plaintiffs’ application to adduce expert opinion on liability by Mr. Lo Kok Keung.  As such, there is no need for directions for defendants to adduce its expert on liability and for further witness statements to be exchanged.

34.The costs of and occasioned by the plaintiffs’ application be to the defendants.  If no agreement on costs is reached, the defendants are to serve and lodge a summary statement of costs within 56 days of this Order and the plaintiffs are to serve and lodge a list of objections 28 days thereafter for summary taxation on the High Court scale. Plaintiffs’ own costs of this application be taxed in accordance with Legal Aid Regulation.

Mr. Tommy Lo, instructed by Tang, Wong and Chow, for the plaintiffs

Mr. Shu Lun Yau of Cheung and Yip, for the 1^st and 2^nd defendants