When Boomer and Tyson are confronting the Rental Car salesman at the front of the hotel, Boomer has a cigarette in his mouth, but in the next shot it has disappeared.
The large registration numbers on the side of the speedboats in the chase scene change several times. Tyson and Boomer's boat is initially registration number 27838, however when it hits the ramp and skids across the land into the back of the truck, the registration number changes to 23108. Of the two boats giving chase, registration numbers 43738 and 24118, the former boat crashes and explodes - the number being clearly visible whilst it is on fire. In later scenes, the remaining boat should be 24118, but the number seen several times is 43738.
The screen of the television set used in the first fight against the gang, is smashed/intact between shots.
When Boss Wing shows up with the shotgun, he loads a double-barreled shotgun and then fires two shots from it, however when he confronts both twins, he's holding a pump-action shotgun.
When Tammy and Barbra see both Boomer and Ma together in the bedroom, they both seem to faint on the bed, but in the next shot, which is supposed to be a second later, they wake up on the floor beside the bed. They do however faint on the floor. It's just the carpet that looks like a bed spread.
At 01:08:25, we can see a special effect issue with Ma Yau's and Die Hard's arms (both played by Jackie Chan).
Fingers on the piano often don't match the notes being played.