One odd thing...
Garber asks Petrone to get the names of all NYC train drivers who were fired for just cause. His reason is that one of the hijackers knows how to drive a train and "you don't learn that on Sesame Street."
But how did he know that one of the hijackers was driving the train? When Mr. Blue says, "We have taken over your train," wouldn't Garber assume that Mr. Blue had a gun to the driver's head and was making him drive as instructed? After all, when criminals hijack a plane, they don't kick the pilot out of the cockpit and start flying the jet on their own (not until 9/11 anyway).
I'm pretty sure that Garber did not speak with Mr. Green (even though he overheard his sneezing and said "Gesundheit" a couple of times), so Mr. Green couldn't have told him that he was now the one driving. Also, at no time do I recall Mr. Blue ever mentioning that one of his gang is now the driver.
It appears that the hijackers let the motorman go (they told him to go to the 9 separated cars and order all the passengers out). But how could Garber know this at the time he makes his assumption about a hijacker driving? Also, Mr. Blue doesn't indicate that they let Doyle, the NYC driver, go.
... unless I'm forgetting something.