Stupidity: Monk steals the magazine from Coffey's SIG. However, I don't see how he could have jacked the slide to eject the round in the chamber without being noticed. Someone as paranoid as Coffey was at this point would not have left the chamber empty. (Just FYI, when you load an automatic pistol with a magazine, you have to pull back and release the slide to load the first bullet in the barrel.)
Suggested correction: Since we are never shown that Coffey did chamber a round, we cannot assume that he did based on his personality alone. Therefore this isn't a plot hole. However, it is ridiculous that he is threatening people with a gun without a chambered round. This entry should be listed as "Stupidity."
SEALs don't carry weapons without a round chambered. The "maybe" here falls much more on the side of the round being in the chamber. And "Stupidity" wasn't an option available when this entry was originally submitted. :).
Stupidity: It was pure stupidity for Riggs to bring Rika back at her residence after escaping the hit on Riggs. The villains know where Riggs' love interest lives and this nor the option to hide somewhere else or safer never occurs to him?
Stupidity: When Rumsfeld is on his roof as a look out, he has a clear view of the neighborhood, even at night. However when the Klopeks first come home that night (and realise that someone is in their house), Rumsfeld fails to notice their car until they return again with the police. (01:20:00)
Stupidity: Suspension of disbelief is fine for a movie like this, but even as a child I found unbelievably silly the fact that the Ghostbusters use a Nintendo controller to move the Statue of Liberty. The concept is never set up and never is shown properly; all the movie showed and told us was that items possessed by the slime dance wildly to the beat of music. There's no logical (as in, movie internal logic) passage between that and "so we fire up some beats and it won't start dancing to it, but just calmly move according to our inputs on a joystick."
Stupidity: Any fighter pilot should know better than to attempt a low flying attack so close to a hill, let alone into a tunnel. How could he not know that it was there? How'd this moron even get his pilot's license?
Stupidity: At the start of the tanker chase Sanchez shoots at Bond. He manages to get in the cab and throw the driver out, who lands on Sanchez's car. Sanchez then gets in front of Bond and has the ideal opportunity to just shoot the cab up with his machine gun knowing Bond is driving, but he doesn't.