Miguel Indurain apparently used a clincher front and tubular rear. I guess he was wigged out by crashing due to a rolled front tire but a rear tire normally (I said normally) results in either a slide or just a hairy skid to the side of the road.
I think Beloki's crash was a result of a poorly glued tire (it happens, esp in stage races, esp to those who get new tires the day before). I was watching the Z team work on bikes and they found cuts in a couple tires and just super glued them. But when they found something in Lemond's tire they replaced it. Problem is that the glue may not be set by the time they started racing the next day. Lemond didn't crash (or roll his tire) but a totally tired mechanic in the Tour? I could see that happening, esp after seeing things like err the PDM rider who rolled both his tires 500 meters from the line. The Belgian guy who won Worlds in Japan when he went off the front with Dirk DeWolf. He became a commentator on TV and died in a car crash shortly after he stopped racing. Name escapes me. I must be getting old, I always admired this guy.
cdr