When Susan is on her father's boat during the party, her necklace disappears and reappears between shots.
When Arthur falls into the boiler room and crawls behind the machinery, the stunt performer stops when he thinks he's hidden, but his shoes and posterior are still visible to the camera. Even though we can still see him there, Arthur is already up and walking out of the place across the room from this.
When Arthur enters Bert Johnson's yacht and is walking through the main cabin filled with Christmas party guests, a boom microphone operator can be seen on the right side of the screen.
The Bachs would not have invested all of their money in the same company.