I joined Websleuths to comment on this. The death of Chris Hyndman was a big shock here in Toronto. I find myself in the uncomfortable position of being able to comment on the two different possibilities, suicide or misadventure while sleepwalking.
It is true that, in the past, being not straight in much of Canada is especially hard for young people. I was lucky enough, I suppose, but those experiences--the feeling of being isolated, the pervasive sense of threat and despair--can stay with people even after things have gotten better. I don't know Hyndman, but I wouldn't be surprised if this was the case even with his happy life. Who knows what demons may have haunted him?
It's also true that sleepwalkers can do remarkable things. I have been diagnosed in the past with significant sleep issues, frequent wakings and periods of apnea and even sleepwalking. I have no recall of everything that I may have done, but I do dimly remember one episode when I got out of my then-partner's bed, walked over to the kitchen, and urinated in the kitchen garbage. I should go without saying that this is something that I never do in my right mind. At the time, as I walked, I felt as if I was experiencing some kind of dream. In retrospect, it is terrifying.
We know that Hyndman had serious issues with sleepwalking, and sleep. If his mother's testimony is not enough, he himself spoke to the Toronto Star in 2007 or 2008 about his serious sleep issues. It does not seem at all implausible to me that, sleepwalking, Hyndman may have walked off his condo balcony as readily as any dreamer might do anything bizarre in a dream. (If that is the case, I hope he did not wake up on the way down.)
In the end, we can know nothing. I can't think offhand of any way to distinguish between an intentional suicide and a misadventure while sleepwalking. All that we can say for certain is that a man died prematurely, and that we are all the lesser for his departure.