The videos of the spectacular Bauge/Sireau sprint have been fluttering around the cycling blogs for the last few days. I just came across some shots taken by Cycling Weekly from Sireau's perspective.
Unfortunately it doesn't show how the crash started, but basically, Sireau's bars hooked Bauge's left leg and lifted Sireau's front end off of the ground. When his front wheel landed, it was a strange angle and caused the tubular to roll (I've had similar crashes in Polo because of hooking bars on a big guy's legs).
At this point contact has already made and Sireau's front tire/tubular is sliding off the front wheel.
Falling onto Bauge's rear wheel. Ouch.
Sad Clown face. I think he's realized whats happened and that the race is over.