I've seen him ride as well and watched the broadcast last week. I race mx and know Red Bud quite well (I'll be there in a few weeks for the Vet Series).
Red Bud is a long track and challenging --- always has been. The problem with heat stroke is that you become progressively more disoriented and that in turn leads to making bad decisions. He should've taken the first signs of heat exhaustion as a warning to pull in, but instead chose to try and finish instead. I understand that perfectly as I've been in similar situations when racing.
Godspeed.
