There Goes El Neighborhood - S3-E9
Continuity mistake: When Junior and Cecilia are talking in the cafeteria, a boy with a blue waistcoat can be seen in the shots of Cecilia. The boy is eating a sandwich, and has a cup on the tray in front of him. In the shots of both Junior and Cecilia, the boy has no tray in front of him and is holding a milk carton instead of a sandwich. (00:08:45)
There Goes El Neighborhood - S3-E9
Other mistake: Cleveland had a VIP Sky Box installed for the big game. Yet when Cleveland is actually watching the game not only is he not sitting in it, but there is no sign of it either. (00:00:45 - 00:03:35)
Answer: In the episode "A Rodent Like This" Rallo discovers that Cleveland Jr. is actually a secret agent who is tracking down Tim, who is actually criminal. Jr. reveals that in order to get close he had to eliminate the real Cleveland Jr. luckily Cleveland doesn't pay attention so it was easy. Whether or not this is canon or not depends on the writers.