Everything gatehouse said in your quote is ligit.
Absolutely legit.
You don't need to photocopy, make scans of PAL's or squirrel away the buyers information for your personal files.
You don't need to call the CFC, check birth dates, call in the ammo transfer or check his place of birth.
It's just ammo. It doesn't need to be a complicated process, despite some people wanting to complicate it.
Nobody should sell ammo to anyone they have reason to believe does not have a PAL.
This is simple stuff here. Not everyone wants it simple, I guess.