Continuity mistake: When the villains get the last of the plutonium out of the cache, we see one villain shoot the chain suspending a concrete cap; causing it to fall and close the hole. A short time later, we see Maggie exclaim that the plutonium is gone. The cap could not have been lifted because all the miners were taken away, yet the cap is gone and we can see into the cache.
Continuity mistake: When the door gets blown in the room where Arnold Schwarzenegger (with a bag over his head) was strapped to a chair, Arnold and the chair fall down. From the shot behind him, you can see his right hand gets freed. Moments later when they help him back up, both his hands are strapped again. (00:06:00)baanerp
Factual error: In the opening sequence, there's a bit where they lower a door/ramp at the back of the plane to load jetskis onto it. They only show the door opened from inside the plane, probably because looking at it from outside, the actual plane tapers off towards the end, and doesn't have space for a large access ramp like that. (00:12:15)
Continuity mistake: When the men are being attacked after spending the night in the abandoned town, the horde of people attacking them are all in dark colors such as gray and black. If you watch carefully, you will notice one man in white attacking. This man is shot down and dies, but a few seconds later he is alive and attacking still.
Continuity mistake: At the beginning of the movie, Dolph Lundgren throws down the battering ram which has "Knock Knock" written on it. Shortly after one of their vehicles reaches the top of the ramp and one of the enemy jeeps falls off the roof Jet Li screams "Shut up, Gunner!" at Dolph Lundgren. Just before he screams, the "Knock Knock" battering ram is back in the retracted position. A few seconds later, it is facing the front again. (00:03:50)
Continuity mistake: At the beginning, when the Expendables and Trench are leaving the interrogation room, we see Jet Li along with his main weapon leaving with them, but in the next shot, he picks up his weapon and leaves the kitchen.
Continuity mistake: Just after Billy dies, Barney says "let's take care of him" and Toll Road puts his cap on. In the very next shot as they walk away Toll Road's cap has disappeared.