The One With Phoebe's Birthday Dinner - S9-E5
Deliberate mistake: Across the whole show, whenever Ross closes his apartment, the door remains unlocked; but in this episode, when he and Rachel go outside, the door locks itself. (00:07:00)
Friends (1994)
1 deliberate mistake in season 9 - chronological order
Starring: Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matthew Perry, David Schwimmer, Matt LeBlanc
Visible crew/equipment: During the scene when Phoebe breaks into the other Phoebe's house and gets caught, the older Phoebe was telling the younger one that the man in the photo is not Frank Buffay, but is Chuck Mangioni. Right after that, as Phoebe 2 walks towards the camera, you can see that the door behind her moves open, and there is a visible shadow of someone who walks by that doorway. (00:19:00)
The One With Chandler In A Box - S4-E8
Monica: Fine, judge all you want to, but [to Ross] married a lesbian, [to Rachel] left a man at the altar, [to Phoebe] fell in love with a gay ice dancer, [to Joey] threw a girl's wooden leg in a fire, [to Chandler] LIVING IN A BOX!
Trivia: Matthew Perry's wit is so legendary that the scriptwriters have often incorporated his gags into the show.
The One With the Sharks - S9-E4
Question: What's the name of the "scary painting" that Joey saw in the apartment of the girl he thought he'd slept with before? The strange and creepy painting (black and white, with an amorphous body and a chair). I really, really want to know who is the artist. Not Gladys - that's Phoebe's painting that comes out of the frame.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.