Continuity mistake: During his questioning inside the house, Clemens' hair goes back and forth from falling over his forehead to brushed back several times between takes. (00:05:00)
Continuity mistake: Gerald holds the wine glass upside down, taping the broken stem back on. But when the shot cuts, he's instantly holding it upright instead. (00:14:30)
Continuity mistake: When Clemens is stopped by the police, the shoulder of his raincoat is clean, then has wet leaves all over it, then is perfectly clean again. (00:02:30)
Continuity mistake: At the end, Stella rips open the female impersonator's blouse, exposing his hairy chest. But in the following shots, the blouse is once again buttoned up tight. (00:49:00)
Continuity mistake: In the dining room, Mary places the telephone on the kitchen counter by reaching through the double doors over the bar. The doors, which she pulls shut, bounce back open slightly on their own. Mary then commits suicide. No one else has been there, but when Agatha returns to discover the body, the bar doors are tightly shut again. (00:35:10)