Some evidence does exist which tends to support the gunshot explanation of the Waco FLIR flashes.
First, there is the autopsy of Jimmie Riddle. Riddle is a Davidian who was found shot through the head. Davidian gunshot deaths on April 19 have traditionally been ascribed to suicide as the fire spread and desperation (either at the thought of burning or the thought of surrender) spread. But Riddle's blood analysis showed no carbon monoxide: he had died before he inhaled smoke.
Second, there was Carlos Ghigliotti's remarkable effort to link FLIR flashes to images of persons on conventional videotape. Only a few days before his death, Carlos told me he had found a solid link between a person taking a shooting stance and the occurence of a flash on the FLIR. Where that was, we will never know. BUT I do recall Carlos showing me one conventional videotape, in which you could see an agent, to the left of a tank, seeming to take a shooting stance, then looking backward and realizing he was on camera, and ducking down in front of the tank.
Only recently did I locate what I am very sure was this sequence. It is on a tape the FBI identifies as "CBC Wild Feed" (but which, contrary to its name, is not a Canadian Broadcasting Co. tape). My version is a lot less detailed than Carlos' was: on his, for example, I remember seeing the flesh color of the agent's face as he turns back before ducking down. Here is the relevant segment of mine (warning, long 2.7 meg download): watch the person standing left of the