I thought the it was illegal to change lanes in an intersection, to prevent shit like this from happening.
I've often wondered though about a similar scenario on the freeway though - I've always heard that if I hit rearend another car, I'm always going to be at fault. But, for example, if I rearend a guy who enters the moving lane from a slow/stopped lane of traffic, how do I maintain "assured clear distance" with a car that's not actually in my lane until the last second? Would that be tricky or is there a clear designation there?