Deliberate mistake: While Bobby's parakeet is flying around downstairs, before the bird settles down on the TV set there are two closeups of Bobby which are flipped shots, note the furniture and Bobby's PJs. (00:07:00)
Njorl's Saga - S3-E1
Deliberate mistake: Eric Idle's 'Stock Exchange Report' (in Series 3, Show 1) has a very obvious edit in the middle. This is a monologue delivered without cutaways, so the jump in the video tape is very easy to spot. Whether this edit indicates material removed or a simple joining together of two takes is unclear. However, since Idle gets drenched with water at the close of the routine (and given that, under BBC constraints, there was no time for drying out), we can assume that he must have made his fluff quite early on in the piece.