Why would he have his passport in his shoe?
I have no idea why.
The point is not that Leo carries his U.S. Passport in his shoe, but rather that you now need a passport to travel on the Greydog Bus from Philly to D.C.
I'm just guessing, but....
When he would arrive at the Supreme Court building, he would probably need good ID to identify himself as he submitted his motion with the clerk.
But en route to the SC, he did not want to be easily identified. Probably carried either no ID in his pockets or maybe even someone else's non-photo ID.
BTW: Again, I do believe Mr. Donofrio has been getting some kind of Obama/DNC/Chicago thug harassment over the past few weeks. Anyone remember the Clintons making Linda Tripp's cat "disappear?"
But, that said, I do not believe that the undercover & SWAT cops at Union Station were looking for Donofrio. I think that was just purely coincidental, and pushed a nervous guy to imagine all kinds of things.
Hence, I don't think it had anything to do with the passport's RFID.