Plot hole: When Chris Tucker phones his girlfriend from from the mansion, we see the 2 detectives, staked out in front of the girlfriend's house listening in on the call and trace the call to Beverly Hills. At the end of the call Tucker tells her that he's "on his way over". The detectives apparently aren't too concerned about this or forget, as when Tucker shows up, they are still casually sitting in the van. They haven't called for backup to set up an ambush or anything, no, -one of them is asleep and the other decides they should go check out the girlfriend's apartment after seeing a light go on.
Suggested correction: As we who have seen the film all know, ol boy with the grey/white hair is actually a crooked cop and the younger hothead listens to him. Even when Tucker shows up at the house he still doesn't reveal that he is a crooked cop, not until he has the diamonds does he do that. It makes perfect sense for them not to call for backup, and they use her turning the light back on as proof that he has shown up showing that they heard him say he was coming.
