The pilots leaving creates an obvious issue - who'll fly the plane?
It's potentially another bargaining chip for the negotiators. You want to leave? Fine, release the hostages.
Of course logic doesn't always carry weight with terrorists, who don't exactly look for logical reasons to start killing people.
Tough call. One I'm glad I don't have to make.
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"I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered. My life is my own."