Looks like the tail section just caught the edge of the grass and dug in a bit and caused it to flop like that. By the way, the bike was barely damaged in the crash. He retired (at least for now) witha baby on the way and is selling the bike. I don't know too much about it other than it's a 600 and completely race ready. If interested, let me know and I'll try to get more info for youor pass along his number.