Other mistake: When Cleveland attempts to use the toilet bar, the handle is on the front side of the tank. Cleveland then lifts up the seat and the seat is able to rest on the front of the tank easily. But there is a flusher on the front side and the seat could not have been able to rest on the tank easily if the flusher was there blocking the seat. (00:13:25)
Continuity mistake: When Cleveland finishes his toilet bar, the tools and blueprints on the floor change position between shots. (00:12:40)
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.