Continuity mistake: When Marcus sees his baby grandson, a nurse in the background is picking up a white diaper. In the close-up the diaper is now blue. (00:03:35)
Continuity mistake: When Marcus and Mike drive towards the hospital they drive through a sandy beach and dust covers the car, but when they park the car is spotless.
Continuity mistake: When Marcus is holding his baby grandson, the position of the woman next to him is inconsistent in every single shot. (00:03:55)
Continuity mistake: When Marcus opens the Porsche's door, his left arm is on top of the car or lowered depending on the shot. (00:03:20)
Continuity mistake: When the Captain, Detective Lowry and Rita walk to the elevator, she is wearing black boots. When they exit into the ops room, she's wearing high-heeled shoes. (00:35:40 - 00:36:40)
Factual error: When Armando fired the M141 SMAW-D from the helo, there was no back blast out of the other side, not to mention the other man is the back would have maybe had his face blown off from the back blast also. (01:20:10)
Revealing mistake: During the first chase, when the Batmobile joke is said, skidmarks from previous takes are visible on the road. (00:02:55)
Continuity mistake: In the Mexico hideout, when Dorn gets through the door with a cheerful "¡Olé!", the jacket on his shoulder changes length between shots. (01:35:15)
Continuity mistake: When Marcus asks to switch seats with a passenger who is all too eager to go for it, his left hand changes position between shots. (01:32:00)
Other mistake: After Mike is gunned down, Captain Harris visits the AMMO team hard at work to figure out who could have done it. However, it seems unlikely that they are so dedicated to their job that none of them had time to change clothes when we see another briefing after Armando's three other killings, which happened across at best days, more likely weeks, or the six months of Mike's recovery. Everyone is wearing the exact same thing. (00:19:00 - 00:21:00)
Continuity mistake: When Rita bails out of babysitting, she says, "Oh no, I have to work," pointing inward, but her finger is outward when she continues the phrase in the next shot. (01:56:20)
Continuity mistake: When Dorn does a Superman punch on a bad guy during his sortie on the left flank with Rafe, the guy he attacks had a machine gun in the previous shot, but he takes the punch already hands-free. (01:44:10)
Other mistake: Mike has a spycam in the locket, but Isabel tears it off his neck. However, the device immediately stops working. Unless the 5' woman crushed the actual metal instantly in her fist, it should keep working and broadcast at least the audio, even if she snapped the cord free. (01:39:25)
Continuity mistake: Somehow, Marcus got a plane seat right behind Mike. He puts his hand by Mike's headrest, and in the same shot, he removes the hand from that position. But the hand is still there in the next one. (01:30:50)
Other mistake: When Mike goes through Isabel's file, it says that she escaped prison on April 10, 2019. However, the scene is set on August 22 of the same year, 2019 (it says the date right there as it checks "the last 2 months" of phone calls with Dorn). Mike was shot at least 6 months before (it says "six months later" in the wedding scene, which is where he makes his reappearance after the shooting scene, possibly more time passed). Mike was shot only after Isabel got out of prison, so that's impossible. (01:24:30)
Character mistake: The movie is set in 1999. Mike's ex was arrested on November 11, 1995. Mike then tells Marcus that he met her when he was an undercover cop in Mexico, fresh out of the academy, "twenty-four years ago," before he got partnered up with him. However, earlier in the movie, it's mentioned that Marcus has been married to Theresa for 26 years and partnered with Mike for 25 years.
Other mistake: Mike's undercover job ends in 1995 and has to take place before Marcus and him work together. The first "Bad Boys" takes place in the mid-nineties (there's a 1990 calendar but also a Michael Jordan retirement reference, so it's safe to say it's supposed to happen between 1993 and 1995). Mike mentions there that they have been partners at the precinct for six years. Moreover, in "Bad Boys 2," Marcus' yearbook from 1988 has Mike's signature with the Bad Boys motto; they were friends long before the first movie. There was no room for nerdy "Michael" to disappear for possibly years without Marcus knowing and the subject coming up before.
Continuity mistake: When Mike tumbles on the flatbed truck after bouncing Marcus's sidecar out of the way, he rolls head to the left, feet to the right. It's the other way around at the cut. (01:20:40)
Continuity mistake: Marcus, in his half of the sidecar, is on a collision course with a truck (after they show the truck driver steering to avoid Zway-Lo). In the more dynamic, wider angle, he is screaming, body stiff and hands off the machine gun. A close-up of Martin Lawrence shows him still clinging to the weapon. (01:20:30)
Visible crew/equipment: During the chase, Zway-Lo attacks the Bad Boys with a car that is being towed, causing it to explode and fly off the bed of the truck like a projectile. Complete implausibility aside, every time you see a glimpse of the men in the truck cabin, there is a 0 reaction from them. The truck goes on as normal, nobody flinches in the frontal view, the guy in the passenger seat barely glances to the left when Will Smith drives his bike past the window, stone-faced. (01:18:50)
