[reply]Become trapped in/by what?? (seriously, I don't understand what exactly their helmet would be getting trapped in or by, I'm not actually trying to be a smartass here) [/reply]
They get the chin straps caught on the handlebars when they screw up and use the front brakes too hard. Obviously we are talking about something pretty rare I'd think. However, I actually saw that almost happen last weekend. A girl (maybe 8yrs old) locked her front brakes, went over the front, hooked her chinstrap on the gearshift lever (I think) and it popped the strap in half. I guess if it held it might have done the same thing to her that it did to my friend?
Regarding the statistical anomaly...very true. I was just amused that House refused to see any *possible* reason why helmets weren't the greatest thing since the bagel slicer. Every invention has a downside. For me riding last weekend 135 miles in heavy crosswinds with the helmet strap whistling in my ear was annoying as hell. My left ear was slightly deaf for several hours from the constant noise. Since I make my living with my ears this is an absolute no-no. :(