Continuity mistake: Cleveland has glass in his feet, but later in the episode, the glass is no longer there.
Revealing mistake: When Cleveland says "Welcome to the party over here pal!", he is putting his right hand up on the glass panel on the right of him. His right hand is not visible on the Clevelands' right side glass panel.
Continuity mistake: After Cleveland shoots the bear and the Huey Lewis like guy, the gun vanishes when he runs to Donna.
Continuity mistake: When Cleveland pulls the gun off his back, he also pulls of a piece of his skin off as well. When Cleveland and Donna kiss, the wound has vanished.
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.