The position of Alex's head changes after Satan puts him on the couch.
The position and location of the pitchfork by the couch changes between shots.
A pill bottle reappears on one of the shelves as Satan steals the bottles.
The items in Satan's trolley change position a few times as he loads it.
Dougie's mask sometimes alternates positions on his head.
As Satan throws Alex's dad through the window, the glass breaks before impact.
When Satan reaches out to grab the boyfriend to beat the crap out of him, you can clearly see a white man's skin where the gloves nor costume cover.
A member of crew is reflected in the costume shop as Satan spies on Alex and Dougie.
Near the end, after Doug finds the policeman, he rings the doorbell to his own home - even though he just walked out the door and didn't lock it behind him.