Continuity mistake: In one of the opening scenes when Bob comes in from walking the dog in the rain, he dries the dog off with a towel and puts the towel on top of the coat tree. He tries to feed the dog and when it cuts back to the dog the towel is on the floor, then his wife comes in and the towel is back on the coat tree.
Continuity mistake: When Grace and Bob are coming back from their first date, the first shot of them walking along, holding hands, shows that her arms are not in the sleeves of his jacket and it is merely draped over her shoulders. There is then a shot of Marty moving two of the chairs together. In the next shot, Grace's arms are now in the sleeves of Bob's coat (that way he has more excuse not to have her go through the trouble to take it off and give it back to him). After she slaps him, in the shot of her saying "I'm really sorry I hit you," and then kissing him, the coat is draped over her shoulders again. Then there is a quick shot of Bob's reaction as she stops kissing and says "Bye" and the next shot (where Grace opens the gate and runs into the house) shows her arms in the sleeves of the coat again.