Alley Cats - S1-E21
Plot hole: When they are bowling and Grace is losing, she says she's fine with it and she knows how it feels to be her middle sister, then Will reminds her that she's actually, "The baby of the family looking for Daddy's approval." However, in all later episodes, Grace is portrayed as the middle child with a younger sister, Joyce and an older one called Janice. This mistake is made in a few other places through the show, where Grace either refers to how old she is (youngest, middle child etc) incorrectly.

Alley Cats - S1-E21
Continuity mistake: When Rob & Ellen are confronting Grace about how competitive she is, there are several shots of them from the same angle. In some shots there is a red bag visible in the bottom left corner, in others it disappears.
Alley Cats - S1-E21
Revealing mistake: When Will goes to pour himself a glass of whiskey, the brown liquid that is chosen to represent the liquor has foam bubbles on the top of it that resemble the ones that soda has.

Alley Cats - S1-E21
Continuity mistake: Grace unpacks her Scrabble board game from her bag, and puts it on the table, and puts the bag on the floor. Then her friends tell her she is too competitive, so she goes to her bedroom. As she goes, you can see that the board game on the table has now been replaced by the big red bag. (01:10:05 - 01:11:55)
Alley Cats - S1-E21
Plot hole: In the bowling alley scene, Ellen states that Grace would need to knock down 27 pins in order to tie. Will and Grace then have a conversation, and Grace gets a strike with her next ball. They then start gloating that they have beaten Rob and Ellen, but the scores don't add up, and they couldn't go into the lead on that round.
Chosen answer: I'm not from New York so I can't speak for them, but in Chicago it has happened before. not very often though but I do recall it happening. I have also seen no tickets sold prior to the show at all, it was just first come first served the night of the show. That is very uncommon though.
princesskelli