My suggestion would be to treat this as if someone will not remove a particular rating. If this means you take any particular action, or dont take any particular actions, I would do the same in this case.
In this particular case, Zepher had already made his intentions clear.
Signed messages are valid.
@OP - I have tagged your account with a temporary negative rating until such time as you regain access to it.
Once you do, shoot me a PM from both this account, the hacked account, along with a link to this thread, and I will happily remove the rating.
Cheers
I have already advised the particular member to contact theymos to see if he will remove Zepher's negative rating since the original owner recovered his account. I hope this does come to theymos' attention and the negative trust is removed since Jet Cash's and my counter rating are only patches, and does not help restore the person's account to the trust score that they deserve.