Plot hole: In the very last episode of the show, "George Decides To Sta-Local Where It's Familiar", Angie mentions that they conceived their "kids" there, referring to both Carmen and Max. However, the season four episode "George Takes a Stroll Down Memory Pain" showed flashbacks where Angie and George were living with Benny, and Angie was far along in her pregnancy with Carmen. Only Max could have been conceived in the house that they are currently living in. I want to add that in the episode 'Valentine Massacre', George says"What about the first time we made love. What were the odds in Vegas!?!"
Continuity mistake: When Carmen gets kicked out of Allendel in season 4, George and Angie suggest Saint Teresa's. Carmen says no because it's an all girl school, but she ends up going. In season 5, she says things like "the girls will vote for me, and some of the boys too" (when she was running for class president). She also told Angie about a boy she liked whose locker was right next to hers.
Continuity mistake: In some of the beginning episodes, whenever George is at work, you can notice that it was originally called "Powers and Sons Aviation", but later in the show it calls them "Powers Bros. Aviation." We even see the Powers Bros. in a few episodes, and in one episode Mel Powers' son smashes up the factory.
Continuity mistake: In Season 5 Episode 18 "George Helps Ernie See the Cellu-Light" Angie is eating chocolate cake before Ernie comes over. Carmen is talking to Angie, and Angie has two big pieces of cake by her fork, but in the next shot, the two pieces are completely gone, and we don't see her put it in her mouth.
Continuity mistake: When George goes to meet the counselor, the counselor asks George if he wants a piece of pizza. The piece of pizza the counselor is holding changes after 2 shots. The first two shots show him holding a full piece of pizza with no fold in it. The last shot shows him holding a piece of pizza with a bite in it and it is folded.
Continuity mistake: Max gives Angie a charm bracelet for Valentine's Day with her birthstone, garnet, in it. Garnet is the birthstone for the month of January. Episodes later, George mentions that Angie's birthday was in the summertime because when she was angry with him, there was still light out during dinner.