Deliberate mistake: In the shot where the F-14 and F5 canopies are only 3-feet apart, you can see that the writing on the side of MAVs F-14 is backwards. Also, if the F-14 was inverted, with the sun more-or-less above, its cockpit would be in shadow, not with sunlight on the nose, as seen. (00:08:55)
Deliberate mistake: Throughout the entire movie, every time Charlie Sheen is not wearing his helmet, especially when he's out in the field in this tropical climate, his hair is always meticulously combed back, blow-dried and puffy. As a veteran, I know from personal experience that when you take your helmet off, especially in a climate like that, the reality is your hair will be messy, sweaty, pressed flat and most unattractive.
Deliberate mistake: When Sarah, et al are surrounded by the Goblins in Goblin City, the first cannon fires causing an explosion in front of some buildings, one of which has a hanging sign with scissors on it. Later, after the squatty Goblin says, "Hey! I just fired you!" another cannon fires causing an explosion, and the very same shot is shown, only the first one was flipped. (01:20:15 - 01:25:35)
Deliberate mistake: In the prom scene at the end, there is a shot of a couple dancing with his hand on her rear-end. A counselor comes over and hits the boy's hand to make him move it. He complies, they kiss, and he puts his hand back when the counselor leaves. The camera cuts away to a different shot, and then returns to an over-head wide shot of the crowd. Down in the lower left-hand corner you can see the exact scene with the couple and counselor being filmed.
Deliberate mistake: During the gunfire of the Portuguese soldiers at the end, seconds before Jeremy Irons is killed, an old Indian woman is shot in her chest, but the actress/extra forgets to react and continues walking.
Deliberate mistake: There's a bizarre editing gaff in the opening fight of the Director's Cut. At one point, Fasil's sword vanishes (for no real reason) and he starts to do backflips. The scene then cuts away, and when it cuts back, he's suddenly running and has his sword again. A few shots later, he's suddenly doing backflips and has lost his sword again. (It's meant to be Fasil doing the flips.) The editing makes absolutely no sense. It's like they somehow mixed up two different scenes during editing.
Deliberate mistake: In the final battle where El Guapo's men are fighting the townspeople, look closely to see that they are really just fighting Lucky, Dusty, and Ned. When the towns people appear, their outfits are very different from the real Amigos.
Deliberate mistake: While recon platoon is marching in their modified pt uniform, Gunny has "Cojones" call a cadence. Meanwhile Sgt. Webster maintains control of his formation, but from the wrong side. No platoon leader ever marches their unit from the right side of the formation.
Deliberate mistake: When Venus de Milo walks toward the back of the fluorescent "ZOO" sign (presumably on the way to her death at the hoofs of the zebras), the "Z" is reversed (that is, it appears unreversed on the back of the sign). This gives the first three letters of the word "ooze," doubtless because that is what Venus will return to. (The word "ooze" is used earlier in the film in just such a context (00:34:35-00:35:50).) A tree blocks the space where the "e" would be (or rather would not). (01:41:55 - 01:44:05)
Deliberate mistake: The explosion of the ship at the end of the film is actually another angle of the explosion of the house from a few seconds earlier. The craft's explosion is much too small for what is shown in the film.
Deliberate mistake: The filmmakers wanted a scene where Andi is startled by Max as he spacewalks behind her at Daedalus. Given that the only way to communicate in spacesuits is through radio, and the two suits would presumably been on the same channel with the shuttle, Andi would have known Max was coming. Further, even if they were on different channels, why wouldn't anyone tell Andi that Max was coming?
Deliberate mistake: When Howard is being sucked out of his planet by the laser beam the couch ignites but he doesn't.
Deliberate mistake: When Shelly Long is pretending to play a skilled violinist, to achieve this, when we first see this, Shelly's bow is above the strings; hence, no noise.