Factual error: When Rogue tricks the Friends of Humanity into firing on their own helicopters, two men are shown to be immediately parachuting from the helicopter at an altitude of at most, 100 feet. This wouldn't really be possible because jumping from such a low altitude would require the person to immediately deploy the parachute, which in this case would cause the parachute to be torn to shreds by the helicopter's rotor. If a person jumped from that altitude and deployed the parachute after free falling enough to clear the rotor, they would have fallen too far for the parachute to have been effective in allowing them to land safely, if the parachute even opened before they hit the ground.
Continuity mistake: When Rogue is talking to Wolverine through her watch communicator, in the closeup shots the watch is shown to be around her glove, on her wrist. In the wide shot, the watch is either around her sleeve just beneath her glove or it has disappeared entirely.
Continuity mistake: When Sarah resuscitates Cyclops, they are by the edge of the swimming pool. When the shot changes to Cyclops blasting through the screen door, the pool is nowhere to be seen, nor is the puddle of water that was under Cyclops in the previous shot.