Other mistake: After Tango and Cash go down the chute and into the boiler room, Conan approaches them and says, "On the road, this pig and his cop friends broke my ribs, my leg, and my jaw" without an accent. All of the other lines that he had before, he had a Mexican accent. It also seems like all of his other lines after that point are said without an accent as well.
Continuity mistake: When Stallone catches Tango with his sister, he sees a stranger (the Chief) in the screen door in the background. He jumps forward into the door taking it with him, along with the stranger. The shot then shows the door get pretty smashed up, falling apart as they both hit the floor heavily. The next shot sees Stallone picking up a perfectly intact door off a crushed Chief.
Continuity mistake: Towards the end of the movie when they are in their big 4x4 destroying the camp, they jump off a small cliff. It is a night scene so they have their headlights on. They cut outside the truck as it jumps and both headlights work. They go back inside, then outside as it does a hard landing. You can clearly see one light is now out from the impact. They go to another inside shot, then outside after it lands. Both lights now work.
Continuity mistake: Tango is in the FBI agent's house and the guy pulls the handle of his car to get away and his car blows up. Tango flies through the air without his necklace. In the next scene, he has it on again. The guy in the air is clearly a stuntman.
Revealing mistake: When Cash stuffs the grenade in the trousers of the guy with the ponytail and throws him down the stairs, you can see that the explosion doesn't come from the grenade but from the hall on the right side of the stairs.
Revealing mistake: When Tango and Cash hold a bad guy upside down off a roof, Tango has his arms straight out in front of him, elbows locked, parallel to the ground. This would require incredible strength. In the next shot he holds the bad guy properly, held close to his own body with his elbows bent - but Tango appears to be exerting no effort in order to lift the guy at the beginning of this new shot. We can also see the outline of a harness system to hold the bad guy up under the black silk shirt of the bad guy. (01:17:50)Bill McIntyre
Continuity mistake: The scene is at Tango's house where he reaches into the refrigerator and pulls out a plate of spaghetti. He drops it on the floor, the shot pulls away, then you see the plate again, only this time it has a fork.
Revealing mistake: When Cash's stuntman jumps out the window after the bad guy, his feet move out in front of him so that he will land on his back (on an airbag) - cut to next shot and his feet are magically underneath him as he lands and rolls. As (Cash) runs around the street corner it is obviously a stuntman. When Cash runs down the narrow alley he is not wearing a bulletproof vest, but in a following scene he takes one off. (00:07:05)Bill McIntyre
Continuity mistake: In one scene, Tango sees a man looking in through the screen door, he jumps the man and rips open the screen. In the next scene, the screen is back to normal and covering the man's face.