In the last part, when Rachel gives the draft chapter of her book to the friends, she doesn't have any for herself in her hand at first, but in the next shot, you can see that she has one.
When a person is in a coma, he'd have a lot more hooked up to him than this man in a coma does, especially a catheter. Phoebe points out that Monica changed his pajamas. This would not have been possible for her to do since he would have a catheter in.
After Ross and Nora kiss, you can see a camera behind her.
Joey explains to Ross that his mother was attractive too. He then says "Hey, you think its easy giving birth to 7 children?" There were 8 children though, Joey and his 7 sisters.
When they are watching Chandler's mom's interview on TV, Chandler suggests switching station to the film "Weekend at Bernie's" (1989). Rachel responds 'No way!'. However in episode 4.12 "The One with the Embryos", it is revealed that Weekend at Bernie's is Rachel's favorite film.