The One With The Screamer - S3-E22
Continuity mistake: After the play, Joey asks Kate how she is doing, and she says "fabulous". She brings a cup to her mouth, and then does it again from another direction. (00:09:30)
The One With The Screamer - S3-E22
Continuity mistake: When Tommy starts shouting at the duck it changes its position. (00:15:15 - 00:18:00)
The One With The Screamer - S3-E22
Continuity mistake: When Gunther brings Chandler the cup of coffee from the woman at the bar, Chandler does not take it by the handle; however the shot quickly switches to him holding it by the handle. (00:14:00)
The One With The Screamer - S3-E22
Factual error: Rachel's date yells at the theater patrons who are in the gang's seats; one of them has D13, and he screams "you're surrounded by even numbers, does that give you some clue?" However, the establishing shot shows they're at the Lucille Lortel Theater, which has odd-numbered seats on the left - the side they're sitting on. It is also a relatively small house and doesn't have a D13; the outermost seat in that row is D9. (00:04:50 - 00:05:30)
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.