Continuity mistake: When Hunsaker's shot, his eggnog gets all over his tie and shirt. When the camera angle cuts to Murtaugh's reaction, Hunsaker's shirt and tie are clean and there is no eggnog pouring from the container. Also there is no hole of any kind in the glass door behind him in which the bullet made. (01:04:00)
Suggested correction: You can see the eggnog on his shirt and tie. As Murtaugh is kneeling next to Hunsacker it is very visible.
Plot hole: One of the children is a witness that saw the man that planted the bomb in Dixie's house. He is said by a policeman to have been playing 'under the porch' and was close enough to make-out the Special Forces tatoo on the bomber's arm. Problem is, Dixie's house had no porch of any kind, and any other home's porch would've placed him too far to see such a small tatoo so confidently. (00:57:40)
Suggested correction: The rear of Dixie's house is never shown. The house could conceivably have a back porch the kid could have been playing under and the killer could have used the back door.
Trivia: In the scene where Danny Glover and Mel Gibson are interviewing the kids who also saw the hookers house blow up, one of the kids has an orange hat on with a black "B" on it. That is the hat for the younger age groups of a summer baseball league in NYC called the "Bonnies." I know this for a fact because I played for the organization my whole life. Why would a kid in LA be wearing the hat? Only interesting to people from NYC, I guess. (01:01:00)
Suggested correction: "Why would a kid in LA be wearing the hat?" Maybe it was a gift, he moved from NYC to LA, it belonged to a dead friend who played there, he stole it off someone and wears it ironically, or countless other reasons.
Continuity mistake: When Riggs and Murtaugh walk toward Dixie's house before it blows up, they're wearing large clear glasses, almost like the safety glasses they were wearing at the firing range. After the house blows up they aren't wearing them anymore or even seen taking them off. (00:56:20)
Suggested correction: Roger and Martin are off screen for plenty of time to take the glasses off. Most likely, this happens when we see the kids getting on top of the car.
Continuity mistake: When Riggs and Murtaugh kick Murtaugh's front door open they must have damaged the lock, but when the door falls closed the lock sounds as if it is perfectly OK. (01:09:15)
Suggested correction: Roger has keys to his house. It would make much more sense for him to unlock the door, turn the handle, and then kick the door in for quick entry.
Factual error: When Riggs and Murtaugh are at the indoor shooting range, Riggs shoots a smiley face at long range. Every shot makes Mel Gibson blink and twitch from the bang. No expert marksman would react like that to the gunshot. Nor could his shot placement be so accurate with that reaction.
Suggested correction: Unfortunately, it's impossible to state with 100% certainty how everybody would react in that situation or how such a reaction may or may not affect their performance.
Plot hole: Before Riggs, Murtaugh, and Rianne enter the disco after they have killed or chased away their torturers, a man is casually leaning at the bar, with his hands folded in front and moving with the music. When the three protagonists come running through the door he immediately turns around and points a gun at them which apparently he was holding in his hand. One should expect that, in a public disco, even the bad guys keep their guns somewhat better hidden than just in their folded hands when they are not aware of any immediate danger. Furthermore, even the guests close to the bar don't hear the shot when Riggs shoots that guy, even though the music is not loud enough to cover the gunshot. (01:25:20)
Suggested correction: The bit about no-one in the club reacting to the gunshots is a plot hole. The bit about the man at the bar with a gun, no. It might seem strange that he'd be sat there holding his gun, but it's not an impossibility. It's a (presumably) legally owned gun, in a privately owned venue, carried by someone who might be security. There's no reason to presume he's hiding it. Maybe he just likes holding his gun. Regardless, the plot isn't broken because of this; he just gets shot a few seconds sooner.
Plot hole: There is no way Riggs and Murtaugh would have let Joshua kill the two officers guarding the house, if they were already waiting for him. And if they didn't get to the house first, there certainly would not have been enough time for them to reach the house and leave a message waiting for Joshua in that short space of time. So, were they waiting for him or not, and why let two cops be killed if they were?
Suggested correction: They didn't get to the house before Joshua; they showed up after he killed the two police officers. The note is in a child's handwriting, so it's more likely that Murtaugh called the family to tell them to evacuate the house, and one of his kids left the note.
