Other mistake: In the 30th Anniversary version with new footage it is revealed that the first zombie we see (the one that kills Johnny) died in the electric chair. If that's the case, he should be bald with a large burn on his scalp, but he has a full head of hair.
Other mistake: Guy goes to the closet and gets Hutch's coat as he's about to leave after having coffee with Rosemary. If you look at her she looks ghostly as they applied more makeup to her face between shots. Unfortunately they missed some spots around her eyes and on her forehead. (01:06:50)