At the very beginning, Jennifer hears noises in the house and gets Jonathan to check on them...she goes too. They go downstairs in just their pajamas, and Jennifer sees light coming from the kitchen. When they open the door and the camera shot goes from behind them to in front of them, Jonathan is now wearing a robe over his pajamas where he wasn't in the previous shot.
When Jonathan and Jennifer are in the alley with the insurance guy, she gets the gun, puts it under a metal trash can lid, then stands on it. In the next shot, the trash can lid is gone. In the next shot, the lid is back.
The slide isn't pulled back on the semi auto pistol at the aquarium scene.
Obvious stunt doubles for Robert Wagner when he's dodging the van, and for all characters during the fight at the warehouse.