How often does this actually happen? I've read blogs and blogs of races and races, and this has never come up. Unless you can cite specific examples, I'm not really buying it.

One of the first things a triathlete learns, even the most clueless ones, is "what's the deal with aerobars, and why would I even need them?" If someone doesn't tell them, they learn it instantly by experience when they take their very first maiden ride with it and realize that steering is harder on the bars and there are no brakes there.

Of note, what does come up routinely are roadies who overestimate their bike handling skills, and do silly things including peeling bananas, eating CLIF bars, and other non-race related strange behavior that does cause wipeouts. If you don't believe me, this is straight from Rahsaan Bahati's (USA national elite pro crit 2008 champ) most recent blogppost - I didn't even need to go digging to find stuff like this.

"Also, Justin Williams took a nasty spill as some pansy tried eating a cliff bar in a 90min race with 20 minutes to go...yeah that would give you some energy...Idiot. The guy tried one handing the bard in the head wind section and when the flow of the group shifted, the guys swerved and took out Justin. Justin wasn't that pissed about even loosing skin, he was pissed about destroying his national Champion kit. "

http://bahatiracing.com/blogengine.net/default.aspx