Ah, I forgot to point out a couple of things that the truthers might take from this.
The cover note from the tape says Glick's mother-in-law called at 9:20, which is before the hijack happened. It looks like a mistake because they also report Glick saying he'd been in the air for an hour (the plane took off at 8:42), and early on someone says "they just crashed one into the Pentagon", but truthers love their "anomalies" and this will be another one for the list.
Someone later says "there's not much of the World Trade Center left to crash into". This is before they're talking of the attacks, and will play to the argument that the first WTC collapse must have happened by now, so this contradicts the Commission timeline where this happened after the Flight 93 counter-attack begins, not before. (Sounds tenuous, I know, but there really are people who argue this.)