Revealing mistake: When Irma screams at seeing Mr Bean with his jumper pulled over his head, all of the other cinema patrons jump with shock - except for the woman directly behind the two of them, on the right of the screen. She just grins and laughs, forgetting that her character shouldn't be in on the joke.
Visible crew/equipment: As Mr. Bean goes up the ladder to get to the diving board, the camera follows him, and behind him on the wall you can see the light reflection following him. (00:02:35)
Continuity mistake: When Mr Bean is trying to get out of the car park through the entrance, he uses a wheelie-bin to simulate a car to get the gate to open. After he's out and shifted the bin, he's blocked in by another car. We see a hand take the next ticket (presumably belonging to the driver of the incoming car) but the car pulling up in front of Mr Bean is so far away from the ticket machine its not possible for him to take it and drive into the car park in the short amount of time seen, plus we never see or hear anybody get out of the car to get the ticket.
Revealing mistake: When Mr. Bean forces the Reliant to reverse out of the car park and turn on its side, as it lays on its side it is obvious that the driver is a plastic dummy.
Continuity mistake: It's clear Mr Bean is hanging from the diving board by one hand by the time the boy decides to stamp on his hand. When the boy does stamp on him, watch the position of Bean's left arm in the next shot – he appears to be holding on with both hands.
Continuity mistake: Just after Mr. Bean's hand is stomped on by one of the boys, and he lets go of the diving board, the camera pans back to show him falling into the water, but the same shot shows no-one else standing on either of the diving boards. The two boys should have still been standing on the higher one.
Suggested correction: This is only an error in the "widescreen," aka cropped version of the episode. In the original 4:3 edit, you can see the two boys at the top of the screen, but the "widescreen" shot cuts them off.
And even then, the boys' legs are still visible in the widescreen version.