I suspect it may have been a case of making assumptions during an assembly line of departures. Usually, 9 a.m / 10 a.m is a busy time for departures at Pearson. The controller, busy handling other aircraft, assumed the Embraer would be already climbing out by the time the Boeing was ready roll. The crew of the Boeing, making last minute checks, also assumed the Embraer would already be climbing out by the time they were given clearance to roll. Neither the controller nor the 777 crew kept their eyes on the Embraer.
While, it's true that bird strikes happen often and aborted take offs occur probably just as often, things may have been so routine... Enough so that everyone became a bit too complacent. I bet that won't happen again.
Yah.... Good luck with that. Nobody will ever stand trial for that incident, much less be imprisoned. Although, I do understand this is a formality which must be undertaken....albeit in vain.