Hookers, Hookers, Hookers - S8-E4
Character mistake: Gordon says that he never had sex with anyone Alan knows, yet in Season 3 he briefly dated Rose and according to Rose also had sex with her.
Skunk, Dog Crap and Ketchup - S8-E13
Factual error: Despite Alan's general bad luck he indeed wouldn't have to be afraid of the skunks. In reality skunks use their anal scent glands very reluctantly and only if they feel threatened because they only carry a limited amount of liquid and have a rather long "recharging" time. To that effect a skunk that apparently feels home in a suburban surrounding would never feel threatened by a human.
Dead from the Waist Down - S8-E11
Continuity mistake: In this episode Alan says that he gave Judith diamond earrings while out, and that she filed for divorce then kicked him out and he moved in with Charlie. However, at the start, Alan is kicked out, and it's several months later that Judith files for divorce as he receives the papers and it's a plot point in that episode (S1 E8).
Dead from the Waist Down - S8-E11
Factual error: Alan and Lyndsey are playing scrabble. Alan is shown laying tiles down horizontally, and claims that he is using the "Z" on a triple letter score, and the "I" on a double word score, changing "it" to "ziti". This is impossible on a normal Scrabble board - those multiplier squares are all offset from each other except one row, and then they're five squares apart.
Answer: That would be "Corey's Been Dead For an Hour" in season 4, episode 9.
Super Grover ★