“They were withdrawn for a very good reason, however: There was no reasonable prospect of Mr. Bryant being convicted of criminal negligence causing death or dangerous operation of a motor vehicle causing death. As became clear during the investigation, Mr. Sheppard instigated the altercation. He was extremely drunk, with a blood alcohol level of 1.83. And had the charges against Mr. Bryant proceeded, the court would have heard that Mr. Sheppard had exhibited “an escalating cycle of aggressiveness toward motorists.”
It is helpful to look at the wording of self-defence sections of the Criminal Code of Canada, Sections 34-37:
34. (1) Every one who is unlawfully assaulted without having provoked the assault is justified in repelling force by force if the force he uses is not intended to cause death or grievous bodily harm and is no more than is necessary to enable him to defend himself.
(2) Every one who is unlawfully assaulted and who causes death or grievous bodily harm in repelling the assault is justified if
(a) he causes it under reasonable apprehension of death or grievous bodily harm from the violence with which the assault was originally made or with which the assailant pursues his purposes; and
(b) he believes, on reasonable grounds, that he cannot otherwise preserve himself from death or grievous bodily harm.
35. Every one who has without justification assaulted another but did not commence the assault with intent to cause death or grievous bodily harm, or has without justification provoked an assault on himself by another, may justify the use of force subsequent to the assault if
(a) he uses the force
(i) under reasonable apprehension of death or grievous bodily harm from the violence of the person whom he has assaulted or provoked, and
(ii) in the belief, on reasonable grounds, that it is necessary in order to preserve himself from death or grievous bodily harm;
( b) he did not, at any time before the necessity of preserving himself from death or grievous bodily harm arose, endeavour to cause death or grievous bodily harm; and
(c) he declined further conflict and quitted or retreated from it as far as it was feasible to do so before the necessity of preserving himself from death or grievous bodily harm arose.
36. Provocation includes, for the purposes of sections 34 and 35, provocation by blows, words or gestures.
37. (1) Every one is justified in using force to defend himself or any one under his protection from assault, if he uses no more force than is necessary to prevent the assault or the repetition of it.
(2) Nothing in this section shall be deemed to justify the wilful infliction of any hurt or mischief that is excessive, having regard to the nature of the assault that the force used was intended to prevent. [emphasis added]
No one knows what really happened. Mr. Bryant’s version is public record. Mr. Sheppard’s version will never be. Eyewitness accounts vary. See the Crown’s Executive Summary (via the CBC.ca).
This YouTube video has not been independently verified:
The issue of whether the Crown could meet the legal and evidentiary burden to prove the necessary elements of the offences at trial are moot, following the Crown special prosecutor’s withdrawal based upon a lack of “reasonable prospect of conviction”. Note that “lack of reasonable prospect of conviction” is not based upon the perceived lack of moral turpitude or contributory negligence of the victim (although it is unsurprising how many commenters on various media outlets are quick to “blame the victim”; namely the person who died).
 The causation standard in vehicular crimes involving consequential death is the same standard as applies in cases of unlawful homicide, whether charged as murder or manslaughter. That standard requires that the accused’s conduct be at least a contributing cause of the deceased’s death, outside the de minimis range: R. v. Smithers, 1977 CanLII 7 (S.C.C.),  1 S.C.R. 506 at p. 519; R. v. Nette, 2001 SCC 78 (CanLII),  3 S.C.R. 488 at paras. 71 and 72.
 The criminal law does not recognize contributory negligence nor is it equipped with any mechanism to apportion responsibility for the harm occasioned by criminal conduct, except as part of sentencing after the required standard of causation has been established: Nette at para. 49.
 In this case, the task of the trial judge was not to determine, as between the reckless mechanic and the dangerous driver, who was more responsible for the death of the deceased. What the trial judge was required to decide and did determine was whether the appellant’s conduct was at least a contributing cause of the deceased’s death outside the de minimus range. Provided the appellant’s operation of the car was at least a contributing cause of death, outside the de minimis range, the prosecutor need establish no more to satisfy the causation requirement. It is as immaterial here that death was in part caused by a defective braking system as it was in Smithers that death was in part caused by a malfunctioning epiglottis.
 It is worth remembering that, as in Smithers, the offences charged here impose no burden on the prosecution to prove an intention to cause death or even injury. Nor was foreseeability of death or injury in issue. That the fatality was unanticipated or an unlikely result of the appellant’s conduct is not a defence.
 The appellant acknowledges that the manner in which he drove the Chrysler constituted dangerous operation of a motor vehicle. There was no intervening act to break the chain of causation between the appellant’s conduct and the prohibited consequence. The certification did not do so, having been given about one month earlier. Nor did the braking malfunction sever the causation connection when it was the manner in which the appellant operated the vehicle that created the necessity of braking.
 I would not give effect to this ground of appeal.” [emphasis added]
In any event, the exercise of prosecutorial discretion is not reviewable and whether or not the late Mr. Sheppard’s family intends to pursue a private prosecution, or a wrongful death action, or choose to find solace for their personal tragedy elsewhere, is their decision alone.