The view point of the car doesn't take into account the view of the rider. I've come into a situation like that, slowing down and sliding up between the cars when the light turns green. I have an up right seating position and I can see over the cars. In reality how fast do you think the rider was going when he was between the cars? 15 mph seems fast at that proximity from the cars view. Plus - as a rider you want to get out from between the cars as quickly as posible so punching it to get to clear roadway is a good idea. The rider didn't enter the intersection first - the cars were already rolling so he had to punch it to get clear.
I'd hate to see what you'd say about me when I do something like that... Hahaha