Continuity mistake: After Matrix lands on the island and kits himself up, the camera zooms out to show him fully geared up; pay attention to the binoculars hanging from his neck - they are different to the ones he uses a minute or two later. (01:07:35)
Deliberate mistake: When Matrix arrives to the beach and arms himself up, a cloud of smoke appears out of nowhere. This results in a more dramatic shot, but it's totally senseless. (01:07:35)
Continuity mistake: Halfway through the movie, Matrix is checking out the house where they keep his daughter. We then see a shot that shows what he is seeing through his binoculars, as he looks from the left to the right. Strangely, the landscape seems to move in the same direction as he is moving the binoculars, whereas normally the landscape would be moving in the opposite direction. (01:08:15)
Continuity mistake: When Matrix fires the multi-bazooka at the jeep, just before it explodes, a bunch of boxes covered with bushes suddenly appears right in front, most likely to hide all the stuff to allow for the explossions and chaos that follows. (01:08:45)
Factual error: The explosives that Matrix places by the buildings on the island are Anti-personnel Claymore mines. You can see on the back, it says "APERS MINE" (APERS MINE = Anti-Personnel Mine). They spray out steel balls designed to take out enemy troops. The relatively small amount of explosive in them is used to propel the steel balls to lethal speeds. There's nowhere near enough explosive in them to demolish those buildings the way that was shown in the movie. In regards to the point about explosives being inside the buildings and being "ignited by the blast of the mines". There's no way Matrix could have known about the explosives inside the buildings. He was OUTSIDE the buildings, so he would have no logical reason to place the explosives there. Also, some of those buildings were barracks for the troops. There would not be explosives stored in them. (01:09:55)
Continuity mistake: Matrix arrives at El Presidente's house and plants a bomb on the floor. In the close-up shot, grass and weeds appear next to the bomb. These later disappear. (01:10:25)
Continuity mistake: When Matrix is infiltrating the base (just before he blows everything up), and just after he has cut a soldier's throat and planted a bomb, he is confronted by two more soldiers walking along with rifles slung. Seeing Matrix, the two frantically start un-slinging their rifles. Matrix throws two knives at them. Next we see the two soldiers falling with knives in their throats... and the one on the right has his rifle fully slung again. (01:10:35)
Revealing mistake: Just before the guard in his tower gets killed and falls out, you can see the wooden sides have been precut. When he supposedly falls through the wood it parts along the cut line but remains hanging on string. (01:10:48)
Continuity mistake: After killing the guy in the watchtower, Matrix kills 2 more guys coming out of a door, plus 2 showing up from behind. The first of these two falls on the ground, but disappears a second later. (01:10:50)
Revealing mistake: When Matrix hits the button to blow up the village, you can see that there are only cardboard stand-ups of men next to the buildings blowing up. Also, for some reason the top of the watch-tower also blows up even though Matrix never put a bomb there. (01:11:00)
Audio problem: When the soldiers surround the shack and finish firing at it,you can hear a shotgun blast last while nobody shot. (01:11:25)
Revealing mistake: When Matrix reaches Arius' mansion (in actuality the Harold Lloyd Estate), he is rushed at by several soldiers of Arius' private army and starts shooting at them with his RPK. In one shot from Matrix's rear we can see him shooting four soldiers at the same time. However, the two soldiers on the far left drop dead even though Matrix is aiming his weapon to the right. (01:11:40)
Revealing mistake: In the mansion, Matrix jumps to shelter in some flowers and the mat he lands on is noticeable because he bounces and parts of it become visible. (01:12:10)
Continuity mistake: While on the compound, there is a scene where some army guys are driving at Matrix in a jeep. They drive past some random army supplies and are about to surprise Matrix when he turns around and nails them with his rocket launcher. Or he sort of nails them. Actually, the army supplies that they had just passed have suddenly relocated and are crashed into by their jeep. Rewind and play repeatedly for full humour effect. (01:12:12)
Continuity mistake: The rocket launcher. It has 4 barrels. Which means 4 shots. Cindy uses 2 rockets to save Arnie from the police truck. When he is using the rocket launcher when he is saving his daughter, he fires 2 rockets. 1 at the jeep behind him and 1 at the large impassable door. But when you see him fire these 2 rockets, they both come out of the same top right barrel. Why would he need 4 barrels if the rockets come out of a single barrel? (01:12:15)
Continuity mistake: When Matrix has got the gun with an ammo feed into it, the amount of ammo left in the feed changes drastically between shots. (01:12:20)
Continuity mistake: During the shooting scene by the mansion, the same poor soldier gets killed from different angles, again and again and AGAIN.... (01:12:34)
Factual error: The gun that Arnold uses at the end to take out a hundred soldiers would need to be deployed. The kickback would knock even Arnie flat on his back after a few shots fired. And there is no way he could run and shoot at the same time. (01:12:40)
Continuity mistake: During the long shoot-out at the compound, Arnold shoots down a whole army of bad guys. When he reaches the fountain, he shoots at about 3 or 4 people from a bird's eye view. If you watch closely, you can see one of the guards dive on the ground and play dead before Arnold's stream of bullets reaches him. Given what was happening at the time, that may have not been a bad idea. (01:12:45)
Revealing mistake: In the siege at the end, there is a shot where you can hear the squibs (small charges that explode on a stuntman to make it appear he was shot by a bullet) going off on one of the soldiers as Matrix shoots him. (01:13:10)
Answer: Possibly so any surviving enemies they encountered on previous missions and or tours of duty couldn't hunt them down and kill them for revenge.