Factual error: In an early runway scene, a billboard for the film Chicken Little (2005) can be seen in the background.
Factual error: In one of the shots when the 757 is taxiing at Newark airport, you can see in the background an airliner in the new Air Canada colours. The current Air Canada livery was introduced in 2004.
Factual error: The UPS airplane shown on the tarmac at Newark Airport is painted with UPS's new logo, which was not introduced until 2003.
Factual error: During the take off roll, the curtain that divides First Class and Economy class is closed. This is in breach of FAA regulations that state the curtain must be stowed for taxi, take-off and landing.
Factual error: The emergency exits on the inside of the Boeing 757 are designed for a Boeing 747 not a 757. If you look closely the doors are not armed either, which they would be on a passenger jetliner so the slides could deploy if the plane crashed.
Factual error: In a scene in New York's air traffic control tower (I think the one where they show the second plane hit the south tower of the WTC), there is a man wearing a black lanyard around his neck that says "Transportation Security Administration" on it. The TSA was formed shortly AFTER the events of 9/11 thus he should not be wearing it.
Answer: The hole where the plane went into the building is shaped very specifically where you can see the outline of the wings, the middle of the plane, not to mention its size. The holes on the other side of the building did not have this same outline. It wouldn't be difficult to determine that was the point of entry. Not to mention the CNN report focused very heavily on the point of entry hole on the north tower and hardly focused on the other sides because of it until the 2nd tower got hit. They were very clear in the report where the hole was where it got hit. Wasn't difficult to determine with both witness reports coming in fast and the shape of the outline.