Corrected entry: In this episode Roz is supposed to be pregnant. She found out two episodes before that she was going to have a baby. If so, then why is she drinking alcohol with Frasier and Niles? If she's pregnant, she shouldn't be drinking alcohol. You could see her drinking at two different times what appeared to be some kind of whiskey at one point, and then some kind of wine later on.
Corrected entry: This episode shows Niles wants to organise a anniversary dinner for him and Maris, but back in season 4 episode 22 he went through hoops to sign divorce papers and in the end he did in fact sign the papers. So this anniversary dinner seems odd and out of place for the situation currently going on with them both - why would he organise a anniversary dinner for a woman he is divorcing?
Correction: At the end of s04e22, Maris calls Niles and says the divorce papers were a bluff and by signing them it threw her off, so she was willing to go to couples counseling. In later episodes it's revealed counseling was going well. (And just because he signed the papers doesn't mean they became officially divorced).
Correction: "Shouldn't" isn't a legitimate mistake. Plenty of women drink small quantities of alcohol while pregnant with no ill effects, despite recommendations against it.
LorgSkyegon