Visible crew/equipment: Series 17, "Let Them Beat Cake": When the inspector opens his car door just before the chuckles arrive, you can see the boom mic on a pole reflected in the window.
Oil's Well That Ends Well - S19-E7
Visible crew/equipment: In "Oil's Well That Ends Well" in series 19, when Barry runs outside to check on the oil, the scene moves to the left to the neighbour's house, and you can see the cameraman and camera reflection in the patio door window as it is pulled back.
Visible crew/equipment: In Football Heroes, when Barry is holding the locker doors closed and he lets go, look at the second locker, you can see it being opened by a pole.
Parks and Wreck-Reations - S3-E2
Revealing mistake: When Paul and Barry are chasing the lawnmower, just before they go out of shot, Paul stops, triggering the end of his cue.
Visible crew/equipment: At the very beginning of "Breakfast Telly" (Series 1), while the brothers are waiting for their cue, a boom mic and pole can be seen at the top of the screen. (This can only be seen if viewed on a 4:3 tv or a computer screen, viewing it on a 16:9 zooms the picture in and it cannot be seen).
Continuity mistake: In "Matchstick Men" from Series 11, Paul is pretending to be ill, and when Barry is distracting, his trousers are red, but when he enters the bedroom his trousers are yellow.