Other mistake: When Riggs and Murtaugh are assigned as new captains, they throw their old badges to the Chief and he catches them in his left hand as he grabs the new badges out of the desk draw with his right. In the next shot where he passes them the new badges, he is not shown to have swapped the badges over, so essentially he passed the old ones back to them.
Lethal Weapon 4 (1998)
1 other mistake
Directed by: Richard Donner
Starring: Mel Gibson, Danny Glover, Chris Rock, Jet Li, Rene Russo, Joe Pesci, Kim Chan, Steve Kahan
Continuity mistake: During the car chase involving the car driven by the Chinese guy, Murtaugh, and the mobile home, the two cars slide against each other and the right wing mirror on Murtaugh's car is completely wrecked. Once the two cars are separated the wing mirror has miraculously repaired itself. The left wing mirror also does a disappearing / reappearing trick.
Lorna Cole: You look a little banged up.
Martin Riggs: Well, you look a little knocked up.
Trivia: As Mel Gibson, Danny Glover and Chris Rock leave the Chinese restaurant (down the stairs), you can see the umbrella handed to Chris Rock hit him in the face.
Question: I wonder, what was the point of having a gunfight with the armored man at the beginning of the film?
Answer: It was put in the film to introduce the concept of Rianne and Lorna being pregnant and to bring in the joke about the news article about Roger, not to mention giving the film an action-heavy opening.