When Tony and the family get into their cars to go to the yacht-club dinner, the night sky is completely dark. But when Billy arrives at the pier in his boat after they've already started eating, the sky is much lighter.
Ma Harrington has a dish in her hand when she rushes Pat out of the parlor so her sister can be alone with her boyfriend. The dish is still in her hand as she closes the door. The dish has disappeared in the next shot, when Ma raises her hands and then pushes Pat toward the kitchen. Pat enters the kitchen, and Ma comes in after her, eating the rest of her dessert off of the reappearing plate.