Audio problem: When Sam and Tess go to the baseball game, and she asks who is playing, he responds with "The Athletics and the Yanks." When Sam mentions the "Athletics" his lips are saying a different team. (00:09:20)
Continuity mistake: When Spencer Tracy takes Katharine Hepburn to the baseball game (about 20 minutes into the film), several plays supposedly from that game are shown. Some of the plays take place on a diamond that has a well manicured dirt path from the pitchers mound to home plate, while others take place on a diamond with an all grass infield and no path.
Visible crew/equipment: When Kate and Spencer go back to her apartment for the first time, you can see the shadow of the boom mike follow them along the top of the wall then stop.
Visible crew/equipment: When Spencer walks out of his bedroom, you can see the shadow of the boom mike moving (along the top of the wall above the light switch). In the next shot, you still see the shadow of it, however it isn't moving anymore.
Continuity mistake: In the opening scene, when Sam comes into Pinkie's bar as they are listening to "Information Please," in some shots, Sam is having a full meal with coffee and in other shots he has a drink and is eating peanuts.