Goofs

When near the end of the film it is revealed that Holly's male psychiatrist Doctor Heller has all along in fact been her "doppelganger" in disguise despite their obvious physical differences, how could it have been possible for Heller and Holly's room-mate Patrick to engage in that energetic sex-scene on the kitchen floor? The "suspension of disbelief" simply defies logic in this scenario.

Holly is wearing a white dress when her transformation begins. She splits into two naked creatures. After the creatures "reassemble," the reconstituted Holly is magically wearing her white dress again.

In the earlier lay-out, Patrick's apartment shows a direct path from the front door to the kitchen area, and yet, when the Gas Man shows up, he enters the kitchen on an angle as if the kitchen is to the right side of the living area.

The scene in Patrick's apartment where the 'Gas Man' walks into the kitchen, the boom mike comes briefly into shot in the top left hand corner, but is then moved up quickly.

When Patrick goes after the doppelganger in the industrial area, a boom mic is reflected off a car.