After Conrad says "F*** it" and jumps off the cliff into the water, he emerges a moment later completely dry.
At one point, Conrad tapes metal bars to his forearms as a defensive shield. He uses them extensively in one fight. A couple of scenes later, they're gone and never come back.
About 1:39 Vinnie Jones' character is asking for a spare smoke. The direction of his head changes in each cut. You'd get whiplash moving your head that fast.
Just after Conrad is 'killed', the film crew are celebrating in the hut. Behind them are several monitors with McStarley with a Union Flag background. The flag is upside down. The large white band should be in the uppermost left corner, but the thinner band is at the top.
When Paco finds Rosa after they were thrown off the helicopter Rosa calls Paco "Manu", the actor's name.
(at around 1 min) There is a close up of the guard turning the key in a large lock. You can clearly see the lock is already open though.
When McStarely shoots into the water with the shotgun, the supposed splashes of the shotgun pellets are far to the left of where the shotgun is pointing at the water.
When the private jet with the combatants lands in the secret location it appears as "Aitape Papua New Guinea". In reality, that airstrip could not take anything more than a twin otter, let alone a Lear jet.
When Conrad is coming home, there is a Texas Highway 59 sign on the side of the road, a little while later there is a Farm Rd 2335 sign. Farm Rd 2335 only crosses Hwy 67 and 277.