Continuity mistake: When Monty punches that guy at the end, check out how the parting of his hair goes from left to right and back again in one shot as he falls and gets up.
Continuity mistake: When the lads run over the fire hydrant in Jonathan's father's Studie, the bumper appears undamaged. However, when they pull up in front of his house, the right side of the bumper is badly crumpled.
Continuity mistake: When Charlie goes to jail he sits on the bed and bums a cigarette. Then the next morning he is lying on the bed and bums another cigarette. His bed changes heights in each shot. (01:30:50 - 01:31:25)
Factual error: There is a scene in which the Catholic high school boys are lined up to go to Confession to a priest. One of the minor characters is a compulsive masturbator, a recurring gag in the film. He is trying to estimate how many times he has wanked since his last Confession, and Kevin Dillon's character takes out a digital calculator to help him figure it out. The film is set in 1965, about 8 years before personal calculators hit the market. (I was precisely the age of the characters in 1965, and we would have sold our souls to the devil for such a device. It was still science fiction!).
Continuity mistake: About one hour in, Maerose is sitting at the table talking to her father. Every shot from the front shows her with her right arm across her body, but every shot from the rear shows her arm forward on the table.
Other mistake: Most of the obvious misses and awkward parts of the action in the opening can be attributed to the fact that it is revealed a few minutes later being just a drill. However, it does not make sense on any level. The training makes use of live explosives, and at the same time no gunshots are fired but only grenades, with unrealistic trajectories and range. The 'terrorists' don't use their rifles if not to try and bash the good guys on their skulls. That's quite the subpar training, but the top brass are impressed.
Continuity mistake: When the men posing as painters rip off the drug dealers, they place a scaffolding plank to cross to the other building, which they remove from the windows and it falls onto the street. When Chuck Norris enters the apartment it reappears.
Revealing mistake: During the opening assault, notice that the sandbags of the enemy fortifications are more like fluffy pillows; they are squashed under a single person leaning on the bank, and they wobble and nearly fall over when Carrasco himself brushes the hip against them walking by. (00:04:30)
Visible crew/equipment: At the end when the helicopter is hovering above the two guys fighting, we see the shadow of the camera on them multiple times.
Character mistake: Morgan Hiller's father is named Stewart (according to the story as well as credits). But in one scene when Morgan and his parents are having dinner, Mrs. Hiller calls him (her husband) "David" one time (instead of Stewart).
Character mistake: When David Frost interviews the fictional actor Bryan Martin, he adds a last question to the interview saying "before you go" and acts as if the guest is not gonna stay (as it often happens in talk shows, when some guests, especially the more famous ones, leave after their bit is over). However Martin is staying and in fact there is a special mystery guest a bit later that makes sense only if he is in fact staying. (00:02:00)
Continuity mistake: When Gun is having lunch with the Sensei, Gun picks up a bowl of noodles as well as two chopsticks. At first, the two chopsticks are facing outwards. But in the next shot, the two chopsticks are facing inwards toward the bowl. (00:03:53)
Factual error: The movie takes place in Corpus Christi, Texas located in Texas' southern section. Characters are shown speaking with heavy southern accents despite most real life residents sounding nothing like this.
Continuity mistake: In the cabin, the survivor and Howe hear an explosion, and the survivor goes out to investigate. He pulls up a board and unlocks the door, and only closes it after him. When the girl comes up from the basement, the door is closed, locked, and barricaded.
Continuity mistake: When "Highball" scores a strike against the hobo, there is a reaction shot on the 4 homeless guys to the right. The one closest to the camera (rightmost one) is watching with his right hand on his knee, but his hand is on the hat he's wearing in the next shot. (00:58:10)
Other mistake: A long-nailed woman types the opening credits in a computer, but in a couple of instances (the Playboy Playmates, for example) you can see her type away when the credits page is already complete and the names are already there. (00:01:00)
Continuity mistake: Sid Sleaze has his head on a pillow. Then in the next shot, it's gone and then back again.
Continuity mistake: Madeleine's dress sleeves are pulled back when she's first on campus with Grinshaw. Then, when she meets Danny, they're suddenly down at full length.
Audio problem: When the husband (Hector Elizondo) is seated in the barber chair, he's heard talking to the kid, but his lips aren't moving. An obvious audio sync issue.
Continuity mistake: The judge arrives and tells the audience that they can sit down. The guy on the left with a white linen shirt sits and crosses his left leg. Reverse shot, and he is repeating the action, this time crossing his right. (00:03:20)