Revealing mistake: When Spencer Tracey backs his car into the hotrod at the ice cream stand, you can see the hotrod already has a sizable dent before the car makes contact, probably a result of a previous take.
Continuity mistake: Towards the end of the film when Spencer Tracy and Katharine Hepburn are in their bathroom talking, Spencer is in the process of shaving. At one point, you see his face covered with shaving cream. When it cuts to Katherine and then back to him, the shaving cream is spread differently on his face. When it cuts to her again and back, it is different again.
Matt Drayton: When I had ice cream before, I had a special kind of flavor that I liked very much but I can't remember what it was.
Carhop: I'll bring you the list, sir.
Matt Drayton: Oh no. You - you must know what it is.
Carhop: Daquiri Ice, Honeycomb Candy, Cocoa, Coconut, Jamocha Almond Fudge, Mocha Jamocha, Peanut Butter and Jelly, Cinnamon, Banana Mint.
Matt Drayton: Must've been some other place.