Plot hole: The mover shouldn't have been pulled into the mattress because he didn't bleed onto it, which is what was required before, for Julia to come back.
Suggested correction: Something entirely else is happening at the end of the film, as evidenced by the fact the Pillar of Souls then rises from it... something which has never happened before. Therefore, the standard rules don't necessarily apply. Additionally, even if you want to argue that they do, the mattress is still totally covered in blood from earlier, when the mentally ill man cut himself on it... so one could argue that there was enough blood on it still for something to cross through.
Revealing mistake: When Julia first emerges from the mattress and is scrabbling on the floor, you can see the body double is actually wearing a thong. (00:30:35)
Suggested correction: That's actually just groin/buttocks muscle and tissue. If you compare it to medical images, while some features are exaggerated, it matches up reasonably well. The fat/muscle/tissue does almost form a thong-like shape in that area. Furthermore, what purpose would there be to having the actress wear a thong when she's already covered in head-to-toe prosthetics that hide everything? That makes no sense.
