(00:02:56) The shadow of the microphone at the top of the headboard is visible, right after Mrs. Tremayne says "Someone tried to murder me." Then the microphone (shadow) turns to the left towards another actor.
After Diane insists on paying for dinner, Frank declines her offer, noting that he can afford it even on his salary. He takes out his wallet and places money on the table. Diane then later says, "At least let me pay for my half." He obliges. She takes out her purse and gives him some cash. Frank then picks up the money he had put down (which would have covered the full bill), puts her money (covering half the bill) down in its place, and gives her all of his money, which she puts in her purse. Nobody ends up paying for Frank's half and Diane ends up with more money than she started with.