9 days (or even 3 months) isn't a "long time". what is fishy is that OP never came back to sign a message with the other address. also theymos won't recover the account if there's any indication that it was hacked or if it is clear that the account was sold by the original owner, so the account shouldn't fall to the wrong hands.
as for the current owner getting ripped off... that's just the risk of account trading.
edited to add the bolded part.
for me, i wouldn't still consider the account being hacked when it is sold coz of just a day after the account stake a new address the original owner came back saying his account is hacked (after almost 6months of being inactive).
eh... read the OP again. he staked an address less that 2 weeks ago and it got deleted by someone. (btw I edited my post that you quoted above to add something.).
sorry if i missed it. hmm. since he just staked a new address 2 weeks ago, isn't it possible that he deleted it just before he sold the account so when the time comes the account is bought then he can claim that the "hacker" deleted the staked address and posted a new one?