Deliberate mistake: When Tree turns on the magnetic medical equipment, it's somehow strong enough to yank a big, heavy wheelchair up and pin Gregory in only a split-second, but not strong enough to instantly pull the screwdriver out of Tree's hand? Obviously this was done so Tree could have a cool moment where she lets go of the screwdriver and it impales Gregory... but it makes no real sense.
Suggested correction: It does make sense. The wheelchair wasn't secured and contained lots of metal, so it was immediately pulled towards the scanner. The screwdriver had a lot less metal, and Trew was holding it very tightly, and she knew what was about to happen, so she should strengthen her grip even more, allowing her to keep hold of it.
Preposterous. Depending on how they're set, MRI magnets can yank entire hospital beds clear across the room, and even once killed a man by setting off a concealed gun he was carrying. There's no way she was holding onto that thing.