Continuity mistake: In the scene where Mr. Bean is on the roof of his car in the armchair, he has a brick in front of the tire. When he is ready to go he pulls it away and drops it. But as he drives away you can see in the background that the brick has disappeared.
Continuity mistake: When Mr. Bean brings in his new chair after his "incident", he wheels his old chair over to the wall with a minimal gap to accommodate the new chair. But when he is accidentally dropping things out of the gap in his wall, he goes and looks at the mess he has made and the chair has moved forward considerably without anyone touching it.
Continuity mistake: When Mr Bean finds Hubert's hat lying on his shelf beside the clock, he puts it in front of the clock to cover the clock up. But when Hubert's silhouette is seen at the end of the show, it shows him lifting his hat from the position it was originally in - beside the clock.