Plot hole: The convicts remove the radar transponder from the Conair aircraft and put it aboard a tour plane to distract their pursuers. That won't work. By law the tour plane will have a working radar transponder of its own, and two working transponders that close together will show up on radar as a collision. Air traffic controllers would immediately alert emergency services who would, obviously, wonder how two aircraft that had collided had managed to stay in the air. Nobody disconnects the first transponder - Pinball carelessly tosses the second transponder under the rear seat of the aircraft (the implication being that it continues to operate, perhaps on backup battery power). He doesn't disconnect the original transponder either - Swamp Thing, a skilled pilot, does that. There is no time for him to do any of this before he is stopped by the female security guard anyway.
Plot hole: In the scene where Ashley Judd runs away from her attacker and falls into her aquarium he has moved to the bottom of the stairs - there is no way he would have been able to move that full fish tank. It looked to be about a 30 gallon tank - it would weigh about 400 pounds with the stand and even if he slid it with some superhuman strength, glass tanks are notorious for shattering when you move them full. Plus it would've made enough noise to wake the dead - no way she wouldn't have heard it.
Plot hole: The main criminal puts on the "butt inspection gloves" whilst searching the first house, but when Alex sees him through the telescope he pulls down the blinds and has black gloves on. Returning outside, they revert back. However, how does Alex know the criminal donned the rubber gloves (when he describes him to his mother), if he saw what we saw through the telescope - the black gloves?
Plot hole: The policeman survives a frontal crash into the hillbilly's truck at full speed without as much a scratch. (00:24:40)
Plot hole: The scene takes place in Julia Roberts' father's stable. Mel Gibson explains to Julia Roberts that he was supposed to kill her father, a judge, because he was going to reopen a certain case. Gibson says that he couldn't kill him and they became friends. He further explains that he was the one to talk her father into reopening the case in the first place. The problem is, they didn't meet until after he decided to reopen it, since that was why Gibson was supposed to kill him in the first place.
Plot hole: Part of the reason that the Jackal killed Lemont, asides from him being very annoying and money grubbing, was the fact that he wasn't going to give up the blueprints and plans for the device he made for him. Made a big deal about how he had to turn it over, and he tricked Lemont into going out into the testing ground with him so he could kill him. Then in the next couple scenes, the FBI is investigating Lemont's warehouse after they find Lemont's body, and Delcan finds the plans for the device Lemont bluilt for Jackal. This makes no sense. The Jackal was so adamant about getting those plans back, and even killed Lemont over it, it's just baffling to think that he would not have returned to the warehouse to get them after disposing of Lemont. Not doing so lets the FBI find it exactly as shown in the film. The Jackal is show to be very intelligent and has been doing this line of work for 20 years. And as Declan says, he's not inclined to make mistakes... Especially a mistake like that. (01:02:35)
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.
Plot hole: It makes no sense that Martin would be getting the invitation to the reunion mailed to his office (or to anywhere else.) He's had zero contact with the alumni committee, and they're not going to hire a private detective to find him. He also doesn't have contact with anyone else from his hometown who might have forwarded it; his father's dead, and his mother's not in her right mind. There's no explanation for why it would have ended up there except for needing to set the plot in motion.
Plot hole: When Luther places the envelope on the table during the White House tour, he is not wearing gloves, thereby leaving his fingerprints behind.
Plot hole: Regis could have saved himself a lot of time and solved the case much quicker if he had just verified the entries in Carla Town's day planner with the businesses listed. A few phone calls would have told him the entries were forgeries without going to the technician for help.
Plot hole: Marcus told Melena he lived in New Mexico with his parents until he was 5 years old: "My dad died in a car accident when I was five... and my mom got caught smuggling people into the country, so she got 10 years [in prison]." Even though Marcus did not know at the time the real reason his mother was in prison, the murder must have occurred in New Mexico, so it doesn't make sense that she would be serving time in a New York prison. (00:33:20 - 00:34:21)