Update: I retract my vouch. Lewis has just scammed me out of the account. I received notification today that the account email was requested to be changed.
I originally purchased this account on January 26, 2013. I had pushed him for all the account information when possible, and it took quite a bit of time for me to receive the relevant information. With GW2, you need email access to authorize log ins. I needed the information to do so, and while I was waiting for the email to change, there was a period of 3 weeks when I could not log in when and where I wanted to.
After being told it would be done "today" for a long time, the email was finally changed to a neutral email owned by me on February 16, 2013. The last time I heard from him was February 19, 2013, when he asked me how the account was.
Sometime between then and today, March 18, he removed me from Skype and is stopped responding to Skype requests. I received an email today stating that the account email has been changed. For someone who originally complained about the scammers in this world, he sure pulled off a good one. I'm waiting to hear back from ArenaNet, but I'm not hopeful as the account always belongs to the original owner in their book.
I wouldn't be surprised if he provided the wrong information to me to begin with when selling me the account, especially if he planned to take the account back exactly one month later. I'm absolutely positive he is the one who took back the account, as he is the only person with all the relevant information.
Edit: I have all the relevant Skype logs, Paypal receipts, and emails to prove this.
http://www.sythe.org/showthread.php?p=12086606#post12086606