Factual error: During the final fight, Liam Neeson jumps down an aisle to pick up the pistol that is hurled from the floor upwards in the air and shoots the villain in the head. The problem here is with physics. The plane was in radical descent moments before. The pilot eventually brings up the nose. At that moment, the gun and Liam Neeson himself would have been pinned to the floor.
Factual error: Although the exterior and interior of the aircraft in the movie are reasonably accurate, the cockpit does not resemble any real life aircraft, let alone a 767. In actuality, the cockpit looks hilariously unrealistic for numerous reasons. It appears to be a bunch of random panels and pieces of other aircraft and their own designs all stuck together to form something that looks outrageously stupid. They even have a 4-engine throttle in there, even though it is a two engine plane.
Continuity mistake: Just after the captain's death, a close-up on Bill's watch shows its date as '11 07'. At all other times, it says '1 18'.
Other mistake: When Bill is walking into the airport after parking his car, the plane landing in the background is moving way too slow, revealing it to be a CGI plane.
Factual error: Leaving aside that it doesn't look like any real cockpit model, you can tell how fake it is when you look for the FMC, they used PC keypads. (00:09:27)
Answer: At no point is he shown smirking before leaving the plane. In the two shots he appears in before he is shown exiting, the first he is wearing an oxygen mask, and the second shows him straight-faced and helping someone to the front. The reason he looks back after going down the slide could simply just be to see who is coming behind him, or he could be examining the damage to the plane.
Phaneron ★