Top Secret - S5-E19
Revealing mistake: Bobby and Oliver are building a house of cards on a small platform sitting on the table when all of a sudden the house of cards collapses. The reason: the platform moves by itself. Clearly it was manipulated off-screen somehow. (00:01:20)
The Hustler - S5-E21
Revealing mistake: When Mike's boss, his wife and two other guests arrive at the house for a night of pool, the four guests are greeted at the front door, enter the brick entry foyer, and descend the steps into the living room. As the camera pans to capture the guests entering the living room, the obviously unfinished and unbricked end of the entry platform can be seen in the shot.
Answer: The dangling bracelet was used for dramatic purposes - to keep the audience on edge.