When they try to leave the building through the door that says 'Push to Open', the hinges are incorrectly placed on the door. For the hinges to be at all accessible to them, it would have to be a 'pull to open' door, and then they would not be unscrewing the hinges, but knocking out the hinge pins. The way the hinges on the door are shown, the door could not be opened easily, if at all.
When entering the lift shaft, considering they are on the top floor that would mean the lift car is either on the same floor or below them. The car is below and no steel cables visible connecting the car to the lift motor room which would be at roof level in this type of tower block.