Why Forcillo was only convicted of "attempted" murder

With all the media frenzy over the trial of police Constable James Forcillo for the 2013 streetcar killing of 18-year old low-life Sammy Yatim, I was forced to look up some details of Canadian law, which is not something I do regularly or lightly.
Forcillo was found guilty of attempted murder in the case, which I naively assumed just meant that the murder was second degree (i.e. not premeditated). But then I got to thinking, how can it be called "attempted murder"? Clearly, Forcillo "succeeded" in killing the boy, not just "attempted" (no fewer than 9 shots made sure of that). So, what, then, does "attempted murder" actually mean?
According to Wikipedia (and I have no reason to doubt it), under Canadian law, murder is a sub-category of culpable homicide in which a person causes the death of another either by an unlawful act, or by criminal negligence, or by causing them to bring out their own death (through threats, fear of violence or deception), or by wilfully frightening them to death. The other categories of culpable homicide are infanticide (the killing of a newborn baby by a mother) and manslaughter (killing a person in a manner considered less culpable than murder). OK, fair enough so far.
Within murder there are two types, first degree (in which the murder was either: planned and deliberate; contracted; committed during a hijacking, kidnapping or hostage-taking; committed as part of a sexual assault; committed during terrorist activity or while using explosives; or committed in association with criminal harassment or intimidation), and second degree (unhelpfully defined as being not first degree, but basically meaning not premeditated). So, no mention so far of attempted murder.
Again according to Wikipedia, attempted murder in the United States is an "inchoate" crime (meaning a crime of preparing for, or seeking to commit, another crime) where a perpetrator either tries to carry out a murder and fails, or takes a substantial step towards committing a murder (such as buying a gun and writing about their intent to kill someone). So, no one actually dies, which makes sense given the label "attempted". I can't find anything to suggest that attempted murder is anything different here in Canada.
None of this, then, appears to make any sense in the case of Constable Forcillo and our man Sammy. Or does it?
The best explanation I have found for the verdict was in the National Post (and also on CBC), and it all revolves around the rather bizarre circumstances of this particular case, some arcane legal technicalities, and probably an attempt at some sort of a compromise by the jury.
It seems that the jury acquitted Forcillo of second degree murder for the initial three shots he fired, the shots that actually killed Yatim, concluding that his reaction was justified in the circumstances and that he was acting reasonably in fear for his own safety and that of others (argue with that however you will). During the second volley of six shots, though, Forcillo was actually intent on murdering the guy, but given that (unbeknownst to Forcillo) Yatim was already dead at that point, it is legally impossible to make a conviction for murder, i.e. you can kill a guy who is already dead. Ergo, Forcillo was only attempting to murder Yatim with his final six shots, but did not actually murder him.
If that smacks to you of following the letter and not the spirit of the law, you may well be right. But, by the same token, it may well have avoided some Ferguson/Baltimore-style riots right here in Canada, and it may still be enough to chasten the police force into making some serious changes to their training and approach to tense situations.
And don't for a moment think that all this is over. There will be appeals, filings for stays of proceedings, and retrials, and in the meantime Constable Forcillo will be suspended on full pay (which is a whole other conversation we need to be having...)