When Angie is beginning to break down in the apartment, she sees the body is missing from the bed and pulls the bedspread off the bed looking for it. A few minutes later she returns to get into the bed and the bedspread is neatly back in place.
When Angie catches the bird in the bedroom, Mr. Bailey's corpse is breathing for several seconds.
Angie (Sharon Stone) is locked inside an upper-floor apartment of an apparently, otherwise-unoccupied building and is unable, during the daytime, to make her plight sufficiently clear enough to passers-by below by banging on the glass, waving her arms, etc. Yet near the end of the film there is a night-shot taken from street level which clearly shows her windows to be the only ones internally illuminated, which would have been the perfect opportunity for her to bang and wave frantically until either a pedestrian or someone in a passing vehicle finally noticed her. Unfortunately, either this doesn't occur to her, or perhaps she has become too mentally disturbed at this point to realize it.
At approximately 15:10 when Dr. Stephan Carter says the line "In the face of real danger you managed to control the situation." a crew member's shadow moves across the wall behind him.
Supposedly taking place in Chicago (though there's no attempt to give even the barest hint of it being in Chicago -- the apartment building is very LA), but the sloppiness gets very evident when you see the (213) Los Angeles area code on the toy building across from the insane apartment she ends up in (Chicago's area code is 312).
Stone's character, although apparently with no income (she's a temp at a steno temp agency which has no work) or visible means of support, shares an apartment floor (two units on the floor) with a wealthy neighbor, and her apartment has a balcony; she's also able to afford a regular psychiatrist.
When the apartment manager goes to unlock Angela's apartment with his pass key, he only unlocks the one in the doorknob and does not even try the deadbolt lock above before walking away.