What caused this crash?

[Cabbie]

Thats at Summit Point and that first turn they are going through is turn 3.. a tick over 90 degree left heading up a hill.. as you crest the hill blind you actually find that the road kinks slightly to the right... As they went over the hill, the rider came up fast on the inside but ran out of track as he closed on the slower rider.  He then grabbed a handful of front brake and down he went.  That track is not known for its surface by any means.. heavy jerk on the front brake=ride down.

[BastrdHK]

absolutely locked the front......give away is the smoke peeling off the front first.  That is the M.O. for too much front brake.......you are on your face before you even know what happened!  That guy took it on the chin hard, and lucky he didn't eat 600lbs of motorized man to boot.

[crashmoto]

front brake.  looks like he didn't think about on the guy in front being in his intended line, thus had overshot his turn in point, panicked, grabbed front brake etc.. looks like it was a sloppy approach anyway- his mind and the bike were intending to do different things... inexperience going too fast probably

[Big Troubled Bear]

Stupidity