Factual error: Mel and Goldie board a ferry. A visible sign states 'Detroit-Racine Ferry'. Detroit is on the east side of the state of Michigan but Racine, Wisconsin is west of Michigan, across Lake Michigan. The only water route to get from Detroit to Racine would be to circumnavigate the entire state of Michigan.
Factual error: Mel and Goldie ride through Chinatown in Racine WI. Racine does not have a Chinatown and the city is nowhere near as large as they represent it to be.
Continuity mistake: Mel, from the time he gets shot in the butt till when he finally has the bullet extracted from said butt, alternates between walking normally & then limping, has blood on the seat of his jeans & is then bloodless, groaning in pain & then acting as if nothing hurts, then groaning in pain again, etc.
Visible crew/equipment: When Mel and Goldie enter the salon on the motorcycle, you can clearly see the ramp used to help propel the motorcycle forward, just as Mel comes to a stop.
Continuity mistake: When Mel and Goldie go from one hotel wing to another - escaping at very big height on a narrow bridge - Mel is first, Goldie is second. When they arrive, Goldie is first. She didn't have enough space to go ahead.
Factual error: When Mel's character first calls the Witness Relocation Program after Goldie's character sees him at the gas station he talks to his new case worker and tells him that he does not remember him. The case worker then says "You know all us FBI Guys sound the same". The FBI does not run the Witness Relocation Program. It is run by the U.S. Marshals, a completely different organization.
Other mistake: The list of the previous jobs and aliases of Rick displayed on the computer bears an inconsistency, as "Gordon Connover" from Atlantic City is an identity listed as being over in December 15 1979, but "Harding Bennett" begins on October 16th of the same year in Cleveland. (00:12:50)
Plot hole: During the final fight, electricity plays a strange, inconsistent role. Leaving aside the cheesiness of the blue sparks effect, it's quite odd that when said sparks signifying electricity travel up the cable, they do it just up to a certain height at first, but all the way up when it's time to kill the villain - in fact they should have travelled all the way to begin with. Not to mention the fact that Gibson has been touching the metal pretty much all the time and not just when he bodyhooks himself to it with the villain. (01:43:20)
Factual error: The 'zoo' where the final climax of the movie takes place is built in perfect movie logic; it is full of deadly hazards (unmarked, small innocuous looking pond filled with piranhas, suspension bridge that collapses when a 100 pound woman steps on it, etc) arranged in ways that either normal visitors would not be able to even notice (making them pointless in context) or that would cause horrible accidents.
Revealing mistake: In the struggle Goldie Hawn has with a bunch of chimpanzees, a single chimp is able to stir the rope an awful lot, with the rope having a leeway disproportionate to the weight attached - in fact it happens in shots where only the monkeys are shown, obviously taken when nothing or very little was attached to the part of the rope off camera. (01:38:25)
Continuity mistake: Goldie Hawn needs to cross a suspension bridge; in the close-up of her feet, the trademark stilettos just get on the rocky floor scattered as you'd expect, one across the other. They are neatly arranged in the following shot though; I don't believe we have to assume she stopped to properly rest them parallel and upright. (01:37:10)
Continuity mistake: Rick is hiding from Diggs in a small nook, making use of the pipes on the wall. You can see (in particular when the door shuts behind Diggs, locking him in the restricted section) that Mel Gibson's right hand has its fingertips clean, while it's shown as a bloody mess when he dismounts. (01:35:55 - 01:36:40)
Continuity mistake: In the scene with Mel Gibson and Goldie Hawn in bed, when she is facing away from him, folded arm under her head, her hair is styled differently over her forehead in close-ups (for instance when she says "His name is Paul" she goes from having hair parted between the eyes, to a full bang). (01:16:50 - 01:18:10)
Revealing mistake: In the close-up of the helicopter when Rach shoots it from behind the cart asking "Friends of yours, Jodie?" it already shows multiple bullet holes in the back. We saw Rach hit the copter just once before, and in the front to little to no damage. The damage appears to be gone when it takes off from picking up the gunman again. (01:06:10)
Revealing mistake: When the "I'm in pursuit" guy splashes his bike into the cement, not only in the side view is there no fresh trace of Rick's bike (and the construction worker is even using his squeegee as if nothing happened), but in the POV shot you can even see that the bike is coming out of the alley into a solid well paved sidewalk. You can actually even see a camera crew (but this last part of the mistake is discernible just if you slow motion). (00:55:05)
Continuity mistake: After escaping unscathed through the hair salon's glass door, the two fugitives on the bike make a sharp turn left; you see distinctly in the aerial shot how they are going past a dark green car while the police car fails to turn properly. In the following shot the police car is doing the wrong turn, but Rick's bike comes across the green car only a couple seconds later. (00:53:55)