Deliberate mistake: When Larry comes inside the house (right after Kirsty encounters the cenobites and Frank and Julia discuss getting him a new skin), he is absolutely bone dry... but we can hear a steady, heavy downpour outside when he opens the door. Seems like they added a rain sound effect in post for a creepy ambiance even though it wasn't shot with that in mind. (01:09:35)
Deliberate mistake: When Larry and the two moving men are first bringing the mattress through the doorway and it gets "stuck," the camera placement makes it pretty obvious that the mattress isn't really stuck. There's far too much wiggle room on either end for it to be "stuck." (Obviously it needs to be stuck for the scene to work... but still a weird inconsistency).
Answer: Letting the moviegoers know what happened to him, he was no longer human, but a piece of meat to be butchered.