International Law

R v. Gibson-much ado about nothing

By Jonathan Rosenthal

I too was aghast when I read the headline in the Globe and Mail that the Supreme Court of Canada had “shot down” the two beer defence. I was about a third of the way through Madame Justice Charron’s majority judgement when the first call came in from CTV news asking for a comment. By the time I had finished reading her judgement I had fielded three or four other calls from other media outlets.

I was sad to tell them all that the Supreme Court judgement in R v. Gibson had done no such thing and that other than to lawyers and law students the judgement was not very important at all.

The judgement dealt with what is known as straddle cases in the context of evidence to the contrary in the defence of Over 80 cases. Simply put there is a necessary presumption in the Criminal Code contained in s.258(1)(c) of the Code (necessary as it is impossible for the police to obtain a blood alcohol analysis at the time of driving). The presumption, also known as the relating back presumption, allows for the court to presume (if a number of pre-conditions are met) that the individual’s blood alcohol concentration (bac) is the same at the time of vehicle operation as at the time the test is taken, unless there is evidence to the contrary. The evidence to the contrary defence (also known as a Carter defence named after a case bearing the same name) works this way: an accused testifies as to his pattern of consumption (what he drank) and a toxicologist calculates what the accused bac would be based on this pattern of consumption. If the evidence of the accused is accepted or raises a reasonable doubt that he is under 80, he would be entitled to an acquittal.

The calculation is not complex. In fact it is rather simple. Each drink contains a certain amount of alcohol. The human body metabolizes (eliminates) alcohol as well. The calculation of the amount of alcohol in a drink is simple; it based primarily upon weight. The rate of metabolism or elimination is not that simple. It varies and is dependent on a number of varying factors. The average rate of elimination is 15 milligrams of alcohol per 100 millilitres of blood per hour. The range is between 10 and 20 milligrams of alcohol per 100 millilitres of blood.

The toxicologist multiplies the number of drinks consumed by the amount of alcohol in each drink and subtracts the amount that would have been eliminated to calculate the bac at the time of the offence.

A simple example is as follows. Assume a 130 pound male. One beer would contain 30 milligrams of alcohol per 100 millilitres of blood. Assume again he testified that he had consumed four beers over a five hour period. The
period commences at the time consumption commences and ends at the time of the driving.

In this scenario at the time of driving he would have a blood alcohol concentration between 20 and 70 milligrams of alcohol per 100 millitres of blood depending on the rate of elimination. The total amount of alcohol consumed would be 120 (four beers multiplied by 30). The elimination would be between 50 and 100 depending on the rate of elimination (5 multiplied by
10 and 20) and as such he would be between 20 and 70 at the time of the offence and as such if his evidence was accepted or raised a reasonable doubt he would be entitled to an acquittal. In this hypothetical example the rate of elimination would not matter.

However, take the following example. Again assume the consumption was four beers but the time period was only 3 hours. In this example the bac at the time of driving would be between 60 and 90 milligrams of alcohol per 100 millilitres of blood. It would be 60 milligrams of alcohol per 100 millilitres of blood using a rate of elimination of 20 and 90 using a rate
of elimination of 10.

Obviously in one scenario the accused would be entitled to an acquittal and not in the other. In other words his bac would be straddling based on the rate of elimination.

Various Courts of Appeal through out Canada had come to different resolutions on the issue. Until this matter reached the Supreme Court of Canada there existed three approaches.

In Ontario the matter was settled in R. v. Heidman which held that if the toxicologist opinion straddled between over and under 80 it did not amount to evidence to the contrary. This lead to toxicologists attempting to determine an individuals particular rate of elimination. The problem with this was rates of elimination even within an individual vary over time according to a number of factors.

The second approach was known as the “prevailing direction” approach. This approach allowed for the evidence to amount to evidence to the contrary if the range was “more likely” below the legal limit than above.

The third approach was the “some evidence” approach which allowed for the evidence to amount to evidence to the contrary if there was some evidence that the accused was below the legal limit. This approach was adopted by the Courts of Appeal in Saskatchewan and Quebec in R. v. Gibson and R. v. Dery. This approach was categorically rejected in R. v. Heidman.