I know the intersection at St Paul and Commonwealth. From the description, the truck was making a right turn from the left lane on Commonwealth, which is a bit weird but done all the time by tractors with trailers attached. St Paul is a busy street, but is probably smaller than the width of some subdivision entrances around here. The cyclist was going fast and whacked into him.
The thing is, they had set up cycling lanes on that stretch of the road. I'm thinking the cyclist probably did not see the turn signal, saw little traffic in the lane immediately to his left, and assumed there was no turn coming. He might have been looking at St Paul to see there were no cars turning onto commonwealth righting on red. Of course, the truck driver probably was just tracking cars and trying to make the turn in a gap in traffic on a busy street.Edit by Nathan - Continued in 2013 thread here: http://www.wnff.net/index.php?topic=28338.0