The crash was caused by:

Veelers drifting right slightly -- 10%
Veelers being spent and not alert enough to handle any body contact-- 20%;
Cav having to steer left to chase Greipel's wheel and over confident he could pass Veelers in one swing -- 30%
Sh*t just happens in a sprint -- 40%[/

You guys finished?
Listen up.
What really happened is he saw he was not going to win easily so he became in a 100th of a second a pouty baby and threw his shoulder into the closest rider just cuz he felt like it. That's what the best bike riders in the world do. They intentionally try to hurt each other. Look at what Ryder H did to that poor Sky kid. He was pissed that the kid took such a great pull the day before so he sent him into the woods for a little camping trip, like hey Punk, mind your ps and qs buster!
It's just like hockey. Or baseball. A pitcher gives up a homer, so he plunks the next batter. Got it?

It's just Cav's version of Tyler Farrar's acting out which usually occurred back at the bus. Only Cav, as we know, is quicker than Tyler.

(Pink, pink, pink, wtf, wtf, wtf...)