Continuity mistake: When Cleveland tells Junior to ask out Whitney, the door handles on the lockers in the background are on the left side of the locker. A few moments later, the handles are now on the right. (00:02:10)
Plot hole: Cleveland never tells his friends where Cecilia lives. Yet Lester is somehow able to call Immigration & Customs Enforcement and direct them to Cecilia's house. (00:14:05 - 00:15:10)
Continuity mistake: When Junior starts singing and Cecilia joins in making them a duet, the shot cuts to Cleveland. After this it cuts to a wide shot where we can see Cleveland doing nothing. In the next shot, he's suddenly finished drinking from a glass. (00:11:00)
Other mistake: After Cleveland introduces his friends to Junior's girlfriend Cecilia, Holt says to Cleveland he managed to take a picture of Cecilia without her noticing. However there are two reasons Holt couldn't have been able to take the picture with Cecilia standing in the position she was in. One, Cecilia was never standing in that particular position at any point during the conversation. And two, Cecilia was standing next to Junior the whole time. If it was the right way round, Junior should have been in the picture with Cecilia when Holt took it. (00:07:50 - 00:08:50)
Continuity mistake: Junior isn't able to fit through the door after returning from Choni's Cantina (the first time). Yet Junior is able to fit through the door in other episodes. (00:04:15)
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.