When they first drove past, they neglected to stop or even check, and considering that Scott's truck was in pieces, that alone is rather suspect in my mind. When they came back through I got the feeling like vultures were circling around us.
The fire was started at a place in the trail where trees narrowed on both sides and there would be no way to go around the fire without cutting a swath. Large logs were positioned around the center of the fire, and had been poorly set with gasoline (burned off without lighting them completely). It was clear that they were trying to keep us there. We did not examine the trail we had already covered, but I would not be surprised if they created a similar roadblock on the other side of us. If they wanted to set a forest fire, there were much better places to do so.
If we had been a little longer fixing the truck, the fire would have made the trail impasseable, and may have lit the adjacent trees on fire as well. When they saw my lights, they took off... then stopped, put the truck in reverse, then forward again, then slowed down. Then I fired one round to let them know we were serious, and they left for good... in a hurry.
I would place their motive somewhere between ignorant and destructive arson to a predatory entrapment. I can't help but wonder what kind of trouble we would have had if we had stayed on the mountain overnight.