i've popped out twice in races. once i tried to attack the group and when i sprinted off the front my leg shot forward and i nearly toppled. thankfully my 10 second lead was enough that i could veer over the side and clip back in before rejoining the group.

the other time was while i was getting ready for the sprint. not even out of the saddle yet, just that initial surge toward the line. i instantly dropped about 10 posititions...thankfully the guy behind me was alert and went around. scary stuff though.