Reportedly, the passport was found by a passerby, who handed it to a NYPD detective. The identity of the finder is unknown; apparently, the detective did not document the circumstances of the find, and may well not have talked to the man much or at all, so there is a lot that we just don't know about it:
- Where exactly was it found? Reports indicate about three blocks away from impact, and in the "vicinity of" Vesey Street. But how near Vesey we don't know. If east of the WTC and south of Vesey, the passport would have been found pretty much downwind from the north face of the north tower
- Was it found alone and in the open or in conjunction with other items, such as a bag or clothes? The reports that we have don't mention any of this, it's possibly unknown even by the FBI
- Where was the passport on the plane immediately before the plane crash? We can speculate that Suqami had it on him, but maybe he had it in the overhead compartment, or under the seat in front of his, or on his seat. If he had it on him. we don't know where he was in the plane. Could have been inside the cockpit, but as he wasn't the pilot, he may as well have been outside the cockpit, guarding the door, or even further in the back, where they had moved the passengers, doing crowd control.
- When and where would it have exited the building? It having passed through the tower appears literally the most straightforward possibility, but there are other possibilities. The Naudet video of the first crash showed that a smoke/dust plume billowed in front of the tower's north face, and a fireball of burning fuel rose. This clearly shows that the dynamics of the impact and subsequent fuel explosion allowed some of the mass of the plane to stop from 220m/s impact speed and even reverse direction. If the fuel could, so could any other plane content. Another possibility is exiting sideways: The Naudet video also shows that a split second after the plane entered the north face, a large plume of dust and debris exited through the east wall. This in turn was followed by another fireball - but the dust plume front apparently rode ahead of the fire front. I find it conceivable that items such as a passport could have sailed the pressured air that way
You need to keep in mind that it is not unusual at all that some seemingly fragile items survive plane crashes, even when most of the plane completey disintegrated and/or burned. You find ID cards and readable paper on many crash sites. Granted, the probability of a hijacker's passport to exit the crash zone and be found are very slim -
ex ante. But by no means impossible. Many recognizable items from the two planes were found near the towers, such as life jackets, seats, human remains and personal items. Most of them just didn't receive the kind of attention that this passport does, for obvious reasons of interest.
Let's summarize:
- We know that items like passport sometimes survive severe plane crashes more or less unscathed
- We know that some of the mass of the plane did emenate from the north face
- We know that some material ejected from the east face while the disintegrated plane still had momentum
- It is therefore conceivable that the passport exited through the north or east wall
- We don't know exactly where the passport was found, but a position downwind from the north tower is entirely consistent with what we know
- The passport was found
I conclude: As the plane disintegrated into the building and created holes in the north and east wall, the passport was pushed by some pressure wave out of one of these holes, fluttered in the prevalent wind about three blocks towards east-south-east, and landed a bit south of Vesey Street on top of whatever else was there, where it was found and picked up by an unknown passerby and a bit later handed to a police detective, who later only remembered that is was "three blocks away from the crash site in the vicinity of Vesey".
Ex ante, it may be very improbable for that passport to escape the plane and building, but it is not impossible, and so ex post the finding of the passport, the probability of the scenario I describe increases drastically. It's no longer "improbable", it is now a "probable" explanation. Nothing that we know falsifies it.