The only bit of law I know is some communications law I learned over 10 years ago when the Internet was just a twinge in Tim Berners-Lee's cortex. And what I learned only applies in English Canada and may not in Quebec where all this took place.
What I can remember of defamation is that the burden of proof of character damage as judged by a reasonable person (that's the standard in Canada, too) is on the plaintiff. There is also no defamation if a successful defense can be argued. I seem to remember that truth could be a successful defense (I think), ie, what you wrote about me may have injured my reputation beyond repair, but if you wrote the truth, my defamation action against you is dismissed (there may be other legal action I could take, of course). So the kid's parents have to prove damage to reputation.
I have no idea if there would have been criminal charges if the boy's suicide attempt had been successful. My guess, and it's just a guess, is that there would have been no criminal charges, but the parents could sue for damages. The bullying cases that have come up in Canada have been where the bullies physically caused the death of their victim.
As for creation and intent, there is a recognition in English Canada of the moral right of an artist that exists outside copyright, and I would think that the case would be pretty clear that the boy's moral right in his video creation was violated and therefore actionable.
