Great finish, I don't know how the other riders were given the same time as Cavendish either, the gap was huge! Just watched it a second time, and I reckon it was Hincapie's counter-attack just before the last couple of corners that did for Garmin, they seemed to panic and it allowed Renshaw to get the best line through the corner, and then it was game over!
This year is the first time I've really paid attention to the TDF (mainly due to accidentally catching Cavendish's win in Stage 2 on TV) and it's been great, I think I have finally been converted to being a bike racing fan.