Frasier agrees to meet Niles and Daphne for lunch, and tells Caroline about his show he'd done that day. Since when has Frasier's show been in the morning? It is usually between 2pm and 5pm.
In the episode "The Guilt Trippers", Frasier pretended to be Roger (Roz's ex boyfriend); but when Roz's sister visits she doesn't say anything about that. She might have found out between these two episodes, but if so, she still would have rubbed it in Roz's face but didn't.
Randy: Your brother was just telling me how Maris is coping with jail. So, is it true that Maris tried to break out?
Niles: Oh, no, no. Her eyebrow pencil simply rolled out of her cell and she went to get it. It's really the jail's fault for making those bars so far apart.