Did the Earth Move For You? - S2-E1
Other mistake: Ashley is now thirteen years old, but she was nine in the previous season.
Suggested correction: It's not uncommon for TV shows to do this, especially with kids. In this exact show they had a baby Nicky who the following season suddenly was like 5 or 6 years old. Other shows like Family Ties and Growing Pains did the same thing. Shows are not always shown in real time when it comes to episodes. They can each take place days, weeks, months or years from previous episodes.
This isn't a valid correction. Just because shows do it or it's common doesn't invalidate the mistake. And while shows don't always have to be shown "in real time", all the other characters would have to make the same jump in age, otherwise it's a mistake.
As Bishop73 said, it's a legitimate mistake because the other characters did not age by four years. There was no time jump. Changing her age does not make sense within the "world" of the show.
Audio problem: When Jerry goes over to open the jail cell door, the sound effect of jingling keys can be heard, however the actor isn't holding any keys. The jail cell door doesn't even have a keyhole.
Suggested correction: When the Sergeant tells Jerry to open the cell (00:18:20), Jerry reaches to his left side to retrieve keys from his duty belt (there is no "sound effect of jingling keys"). And keys were visible dangling from Jerry's duty belt when he told Philip to calm his wife (00:17:10). Secondly, the jail cell door does indeed have an old-style keyhole (00:18:30).