Continuity mistake: In the beginning where Bob and Donnie are watching over the road waiting for the returning troops, the bolt of the M40 rifle Bob has at the ready is closed. In the shot right after Donnie pulls out the picture of Sara, the bolt is shown open, but appears not to be fully open. In the next shot of the rifle, the bolt is again closed. We do not hear the bolt, nor would a sniper at the ready fumble with an arm at the ready.
Mr. Rate: Would've been a bad job to take, though.
Nick Memphis: How come?
Mr. Rate: Whoever took that shot's probably dead now. That's how conspiracy works. Them boys on the grassy knoll, they were dead within three hours. Buried in the damn desert. Unmarked graves out past Terlingua.
Nick Memphis: And you know this for a fact?
Mr. Rate: Still got the shovel.