Revealing mistake: When Briar is reloading cartridges in the flop house, he's removing powder from an already spent shotgun shell. The primer is indented.
Revealing mistake: A brawl in the bowling alley erupts, started by Tex Cobb tossing on the ground a bad Jay Leno stunt double (hair color does not even match). (00:58:40)
Revealing mistake: The bad guy that Nady punches and falls through a hole is a very obvious mannequin. Watch for the close-up of the hand.
Revealing mistake: When Nick cuts in half Tex, if you see closely the hair of Tex changes length showing the stuntman.
Revealing mistake: In the scene at the graveyard, after the Warlock assembles the Grand Grimoire and commands it to say God's true name, the fake headstone behind him starts to fall over. (01:33:02)
Suggested correction: Other headstones can be seen falling before this scene.