After reading this thread
where I'm guessing the kid got/remained banned because of the feedback left for transactions not handled through PBN, I went and checked the feedback forum rules
and discovered that that's not actually listed in there. I'm a huge loser and watch the talk to mods/admins forum relatively closely and from what I've seen it's happened many times before that somebody's trying to mind their own business and keep legitimate feedback and they get banned for having their next door neighbor leave them feedback because the transaction wasn't handled through PBN.
Anyways, I would suggest 2 additions to the rules thread. First, state in no uncertain terms that the deals have to be handled through PBN for feedback to be left here. Second, you may want to add something that defines being "handled through PBN" because if there's a local meet-up to avoid shipping costs, conversations may be had by phone rather than through PBN, and it just generally starts heading into a gray area.