Originally Posted by JDiver

It can happen (but see MAH4546's post for conditions that can impede the award of an SWU). I've anonymously made available SWUs to Pearl Harbor veterans attending (what could well be their last) Pearl Harbor reunions (DFW-HNL or return).

And, yes, one can swap seats with a returning / departing serviceperson - I've done that, as well as using "stickers" at the gate to upgrade a serviceperson or vet when seats were available.