Factual error: The sisters run out of fuel for the helicopter, which is then shown slamming down on the ground and essentially destroying itself. All helicopters are capable of autorotating safely to the ground in the event the engine(s) quit. Of course, that would not have been as dramatic. (01:05:15)
Continuity mistake: The helicopter that they use to rescue "dad" gets its windows entirely shot out. That is why the helicopter is put on autopilot so that the prison tower can be blown up. Later, everyone is sitting in the back of the helicopter talking and all the windows are intact.