The brothers had 'similar' names but apparently not identical names and were both heading to Tokyo but on different airlines. I'll guess the brother in question was booked on UA32 which is scheduled to depart about an hour earlier.
Maybe a simple explanation but from a security perspective, if he had luggage on UA32 which was already in the air I would have expected that aircraft to divert as well. Either way you're correct - very strange and something doesn't quite add up.
Maybe he just didn't want to fly UAL - they've had a tough year
Last edited by b1lanc; 28th Dec 2017 at 01:15.