When the two gangsters are in the Santa Avila store messing with the slot machine, a car is parked in the front, but in the shots after the owner confronts them, the car keeps changing positions.
When the gangster calls Dan after the trial, he starts dialing before the coin completes the drop. In order to register a dial tone on a payphone, the coin needs to complete the drop, then it takes a moment for the dial tone to kick in. Additionally in that period, numbers were at least 6 digits, but he only dialed four.
Rose said she met Nick in the same hotel when he came to San Francisco to have a good time and he asked her to marry him. But when the Nick character is finally introduced, he's a hardworking fisherman in a small town with little time for leisure. In addition he is religious, moral, and of humble means. He gives no indication of the type of person that would go to an upscale hotel in San Francisco and interact with a prostitute.
When Rose returns to her old hotel room to retrieve her wedding dress, she lets herself in with her room key that she held onto; after opening the door she knocks to make sure nobody's in, which doesn't make sense. The character made an error; she was meant to knock first, then open the door if there is no answer.