Shortly after Nix has two fingers cut off her right hand there is a close up of her hand holding a hammer aloft with all her fingers intact.
At 02:35 Nix's car is quite clearly hit by gunfire in the rear, leaving numerous bullet holes, but in all subsequent shots there are no bullet holes in the vehicle.
When Miles shoots the guy in the neck in the scrapyard, the on-screen Righty Lefty ammunition values are swapped by mistake.
Right after the large explosion near the end, Nova tries to run away from Riktor. As they struggle, a large piece of plaster falls off the wall. Moments later, as they rush to the stairs to the helicopter, the piece of plaster is back in place.
When Miles is trying to pick up the hot dog, there is barely any cheese on it, however, when he eats it, the dog was slathered with cheese.
Nix comments on Effie's two "AA-12s". An AA-12 is a "combat shotgun". When she fires they are just automatic rifles and not shotguns.
In the office, after Nix shoots Zander (41:27), it can be clearly seen that she is shooting blanks. The casings coming out of the weapon are elongated and crimped to contain just gunpowder, instead of cut off where a round should be inserted.
As Daniel Radcliffe's character is driving along the downtown streets whilst being followed, you can clearly see the road markings have right lane turn divisions for a society that drives on the left (New Zealand) and not the right (USA).
When Miles and Nix are having their car chase, some green traffic lights a visible above cars driving in the wrong direction.
The address shown for Miles' computer at 8:20 is impossible. The highest number in any of the octets is 254 and his last octet is 256.
Nix's neck tattoo has a grammatical error. It reads: "If you can see this your too close". "Your" should be "You're".
The router address shown for Miles' network could not be reached by Miles' computer. The router must be within the subnet of the machine, in this case 17.7.15.1 to 17.7.15.254. The router shown has an IP of 192.168.0.1 so Miles' computer could not contact anything on the internet.