Based on open sources, NSA has a fleet of about 100 vehicles at most in CONUS, so they would be more likely to fly vehicles cross-country if DIRNSA needed to use a fleet vehicle. Having said that, NSA doesn't just arbitrarily get involved in domestic law enforcement cases, even ones involving crypto, so let's wait to see if there's more evidence than a random HN post to support this allegation.
This is a completely fair comment and my source certainly isn't fully aware of the situation...they just relayed what they saw out the window and some discussion among staff. I wanted to make sure this information was recorded for posterity at the time it happened in the (unlikely) event Tim Cook was taken away in hand-cuffs or something similarly dramatic were to happen. I'm hoping someone from Apple feels brave enough to confirm the events here on HN. Ideally with a few pictures showing the motorcade. I doubt Apple PR will comment.
Honestly, I didn't feel at liberty to ask and none were volunteered. I've been hoping someone from Apple would pick up on this thread and post them here.