Wow, I hope he makes a full recover!
Its a tough call either way. When I'm first at a light (usually between cars) I'm stuck with the choice, jump out ahead of them when the light turns green because they usually forget you're there, or check the sides for the red light runners. Its hard being vulnerable like that on our bikes.
Keep your head on a swivel and expect the worst everyone.
Again, I hope your friend has a speedy recovery.