Update:
So, to the best of our knowledge, here's what happened. When we found out about the serial retractor, we copied and pasted his userid into our blocked bidder list. At that point, we assumed it was done and he would no longer be allowed to bid, but then when Peter posted that he was still bidding, we went back to confirm his userid was on our list, and it was, however there must have been a space before or after the user id and it didn't take. We have deleted it and re-added him to our list, hopefully properly this time
We also spoke to eBay about posting his user id on the public forum and weren't given a clear answer about whether it was ok or not; so, I will provide the userid to anyone who wants it, via a PM to me and we ask that you do not post it publicly, but, we have nothing to hide and want everyone to understand that we do not condone bid retractions.
I hope this helps.
Josh