Too Close for Comfort (1980)

Show generally

Character mistake: In the episode where Henry has overdue library books, they are overdue by 5 years and 23 days. Both Henry and Monroe say in the episode that the fine is around $1000 (based on 10 cents per day due 5 years 23 days)... But in reality, using that calculation, the total would come to only $185, not $1000.

Break Out the Pampers: Part 2 - S3-E2

Character mistake: Near the end of the episode, when Ms. Rafkin stops by to see the Rush family, Sara greets her by name. Ms. Rafkin (who thinks her looks have changed due to a facelift) asks Sara how she knew it was her. Henry told her by her voice which she accepted as the answer. This wouldn't be a possibility since Sara said hello before Ms. Rafkin spoke.

Who Was That Baby I Saw You With? - S3-E7

Character mistake: After the mixup where a baby's grandmother took baby Andrew instead of her own grandson, in trying to track her down, Muriel mentions how since it was the baby's grandmother (instead of a parent), it would be hard to track her down because her last name would be different from her grandson's. This is not fully correct. Generally a baby will have a different last name than its MATERNAL grandmother, but the same last name of its PATERNAL grandmother, so Muriel's comment was only half accurate.