Continuity mistake: After the plane is docked Stallone and Statham enter the customs agency. Statham is wearing a camera on his neck with a small lens, he even shows it to the customs agent. After leaving the customs they walk across a square. The camera now has a big zoom lens attached to it. Statham is not wearing a lens bag. Where did he get that lens from? Also strange is that the lens is set in manual focus instead of automatic. Yet the picture stays focused even zooming in. This is not possible without looking at the screen. Plus the camera is turned off in the close up shot, with the image on the LCD composited in. (00:28:15 - 00:30:45)
Revealing mistake: When the guards enter the room where Sandra is tied to the chair, she kicks her leg out to fight them off but when the chair is tipped over, we see her feet securely tied together. (01:10:44)
Continuity mistake: When we see Barney and the army both racing through the streets, there is a little boy who throws something at the army. In one shot he starts the throw with his left arm but finished it with his right arm. (00:39:20)
Character mistake: When Caesar is showing off his razor, the name is misspelled "Ceasar". (01:07:20)
Continuity mistake: When Barney is driving Sandra's truck there is a shot of it sliding through an open area. Camera cuts to Sandra saying "How can you leave?" If you look out the window they are now driving down a residential street. (00:38:40)
Revealing mistake: When being chased by the military, there is a shot of the blue truck driving towards the camera down a street. In this shot, the tyre marks from previous takes can be seen on the ground. (00:38:00)
Continuity mistake: When the pirate is following the laser sights on his hands, the dots are changing positions massively between shots. (00:04:50)
Continuity mistake: At the end when Christmas and Tool are having a knife throwing contest, the way Christmas is holding his 3rd knife changes between shots. (01:33:40)
Revealing mistake: Just as Yang jumps from the black truck, Barney's truck can be seen doing a sharp turn in the warehouse. However if you look at the floor you will see skid marks from previous takes. (01:00:40)
Continuity mistake: During the car chase, Yang shoots out part of the rear window of an orange 4x4. This hole then keeps changing place between the following shots. (01:00:00)
Continuity mistake: Just as Barney realises it's Gunner who's attacking them, he knocks part of his chrome bumper off the truck and it's dragging along the floor. A few seconds later the bumper is reattached and fine. (00:59:40)
Continuity mistake: When the orange 4x4 is hit by the bin lorry, the drivers side window is smashed. However as the truck pushes the 4x4 just 2 seconds later the window is now intact. (01:00:15)
Continuity mistake: When the contact pulls over and lets Christmas out of the truck, the truck is parked next to some green vegetation. When the truck pulls away it's in a completely different spot. (00:34:40)
Continuity mistake: When Christmas hands his passport over on the island for the first time, the way the customs officer grabs it differs between the CCTV footage and the actual camera angle. (00:27:00)
Revealing mistake: When Christmas is filming the army, you can see the switch on the camera is at the "Off" position. (00:29:30)
Continuity mistake: When we see Barney pull into Tool's garage, his truck is 3/4 into the garage. When the shot changes, it's only just entering the garage. Note the shadow on the bonnet of the truck. (00:22:30)
Answer: The back stories of the individual members of the team have never been elaborated upon. It is never stated where the members received training.
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