You dont get banned because Anet screwed up something.
While I agree you would NOT get perma-banned, saying a mistake could not happen (if they were banning exploiters) is naive…. I get the players anxiety, but it is a wasted emotion as he has no control over what has happened or what will happen about it.
And that anxiety is what I would hope Gaile would address in short order. This bug is extremely easy to come across, and I imagine that most people are just crossing this by mere chance. I had been juggling around the idea of making a Thief a while before this patch, and I just made the poor choice of making one on the day this patch was released.
And because of this bug, I crossed the 5,000 milestone, which grants a pretty sizable pool of stuff — 15g, 400 gems, and a chest of goodies. Are all those illicit gains, because I can honestly say I don’t care for the titles, and didn’t even know of the existence of the HoM room in GW2 until this bug came up. But these items, if accounts are rolled back, are completely up in the air, as is anything else I may or may not do with my account in the interim. What’s the point of playing and getting dailies done, if the next week’s progress is going to be wiped from my account’s record?