Visible crew/equipment: When Eddie says "Pork" to Natasha, Richie jumps up and shouts at him. When he says "She is my fiancee", you can see a boom mic reflected in the Elvis Presley photo.
Continuity mistake: When Ritchie yells "Aah. Aah. Aah." after the table lands on his toes, the shot zooms out. When Eddie hits him again, he is able to move away from the table. But we never see the table moving the final distance downwards towards the floor (implying he's pulled his feet out from under it), meaning his toes were never under the table at that point, only in the short scene beforehand.
Continuity mistake: After Eddie has performed checkmate on Richie, Richie punches Eddie who falls over. Eddie gets back up and lifts the table up. The chess board, ashtray, bottle of brown sauce and other things on the table disappear completely in the next shot showing the table land on Richie's feet.
Revealing mistake: During a few scenes after Richie's finger has been taped back on at an extreme angle, you can see Rick Mayall's real finger bent underneath it. This is most visible after his finger gets slammed in the window: look carefully after the window is opened.
Revealing mistake: Even though you hear it ticking, the second hand on the clock in Eddies' room doesn't move.
Bottom's Out - S2-E6
Continuity mistake: When Richie first gets his head in the fire, the flames become massive. Yet in the next shot, the flames have all died down and all that is left is smoke.