Continuity mistake: When Casper gets on the plane, he starts shooting at Marcus from the airplane door. To the left of the door, there are two windows with tin foil taped over; the airplane is obviously in storage. The taping disappears when he fires again a couple of shots later. (01:46:30)
Continuity mistake: When Theresa gets to Mike's apartment and confronts both real and fake Marcus, she mentions that lying to her is no use because she saw them on the news. Will Smith says, "That sh*t be having a slant," both hands free. In the next shot, he's holding a gun in his right hand. (01:32:10)
Continuity mistake: Inside Mike's apartment, Marcus is fighting with the answering machine. Julia puts the bag with one of her dogs down on the couch. You can see her set the bag next to the gap between two pillows, but in the next shot, it's next to the armrest. Also, the strap is off the couch the next time the bag is in frame once he mentions the "peak hours," but nobody touched it. (00:43:10)
Continuity mistake: When the captain greets the Bad Boys, saying "Welcome to our nightmare," Joe Pantoliano is wearing no glasses, either on his face or around his neck. Cut to him opening the door to the vault; he's now wearing a retainer with glasses. The shots are not technically consecutive, but he was only leading them through a corridor. There's no reason why he'd feel the urge to wear his glasses all of a sudden when he didn't even have them on hand. (00:12:25)
Continuity mistake: After the scene featuring pictures of Martin Lawrence with a big afro, Julia asks him how Marcus's wife is. She adds in a close-up that she must be pretty amazing. Look at her hand, palm against her cheek. That's not the pose she has in the next, wider shot. That's the pose she will get to a few seconds later when she says, "Watching him tonight," etc. (01:18:25)
Continuity mistake: Inside the suite, Julie takes a sip from Max's glass. Behind her, Eddie Dominguez giggles, "Watch your step." He rubs his already powdered nose, then touches the glass. Cuts to a wider angle, and Eddie is repeating the exact same movements - but Julie isn't. (00:25:00)
Continuity mistake: The Bad Boys enter the precinct, made into a crime scene, through an overhead shot. To their left as they come in, a cop in a suit with fair, curly hair makes a turn around a desk corner. It cuts to Will Smith saying, "Hey bay-beh!" tapping Francine's desk. A different cop is behind them, then it cuts to a wider shot with Martin Lawrence in a more subdued greeting, and the same cop from the first shot does the same turn as before. (00:12:10)