Continuity mistake: When Ryan Reynolds is between the two hospital beds, preparing to pull the plugs, there are three wires he grabs to our left (two white and one black). He yanks all of them out (along with another white one to our right) and no plugs remain in the red outlet cover on the wall. But in close ups, as the other agents are banging on the door, we see the lone black wire is still plugged in.
Factual error: At the end when Ryan Reynolds unplugs Israel and Sparazza, both Israel and Sparazza die. Only Sparazza is on a ventilator. Israel is on a regular oxygen mask, which requires the patient to be breathing without assistance, such as a breathing machine. The type of mask Israel was on is not a life support mechanism that would be affected by being unplugged, as it either runs from O2 from a wall insert or directly from an O2 tank, both of which run without electricity. I work in an ER so I know how O2 systems work.
Continuity mistake: When Hugo is shot by Zoot, a spatter of blood comes from the exit wound, hitting the wall. When Zoot puts on Hugo's jacket, however, there is no bullet hole in the back of it when the bullet left.
Continuity mistake: When the police rush into the bathroom towards the end of the movie to capture Sir Ivy, you'll see that as they start to lift him up his left eye is completely covered in blood but when they lead him out of the room is eye is open with way less blood than before.
Other mistake: The assassin disguised as Hugo shoots the black man cleaning up the mess in the back. The black man turns around to be shot again and hurled out of frame. How come the first shot does not elicit more than a slight wince from the black man, but the next shots are powerful enough to let the overweight man fly?
Other mistake: When the assassin disguised as Hugo frees himself after being arrested, he escapes into the adjacent room, closely followed by firing FBI agents. There, he masters the remarkable task of taking off his wig, his mask, his trousers, his jacket and the bloodsoaked white shirt and stashing it all under the bed within two seconds.
Continuity mistake: As the exterior shot of Lake Tahoe advances, the cameras closes in on the roof of a hotel. Beyond, another hotel's facade is in shadow as the sun is behind it, off to our left. The shot sinks through the roof of the closer hotel so our view is now from within the penthouse, but now the facade of the second hotel is in full sun, the light is now coming from the left, but behind the camera.