I don't see how, that wasn't dormer's property it was someone else's and now it's a pile of ashes, I don't think it's impossible for a very strong and athletic military trained vigilante of his own accord to escape through a smokey area where no one could see him, also I have seen the body picture if that is him the burning must be have been pretty erratic because it doesn't look like the shape of his body.
At the bold. I guess they shouldn't have shot back either, because they might have "damaged" someone else property as well right?
Yes, it is practically impossible for him to have escaped. There was hundreds of cops on two tiny streets in big bear. They were surrounding the cabin and immediate streets. They began to tear the walls down throughout a gun fight and when they got to the last wall, they heard a single shot (most likely him committing suicide). No more shots fired at the deputies after that. No way he made it out.
Also, I've seen many charred bodies from fire. They look like piles of black mush. Body shape is irrelevant. The dude is dead.