Continuity mistake: When Greg and Marcia are taping the fake message for Peter, Greg says, "Bang, he buckles down and brings home an A." But when Peter listens to the message a minute later (16:15), Greg's statement is now "Bang, he brings home an A." (00:14:50)
Continuity mistake: The microphone next to the tape recorder moves from one shot to the next. (00:26:05)
Answer: The dangling bracelet was used for dramatic purposes - to keep the audience on edge.