Ok I too got the warning window and the YOU ARE NOW ATTACKABLE, but my character was not tagged perma orange, because I didn't hang around to see. I think the problem here is, non VvV players are getting that message and they chose to continue to stealth around town and ignore it, and now they're orange because of it. When you see the warning, LEAVE IMMEDIATELY. Pvprs complained about blue healers/blockers etc, and this was clearly the way to combat that. So simple, leave when you see the message, dont think you have time to go ahead and complete your trader quest. Come back later and complete it, or become orange.