Hi,
I don't usually post here but this one is easy to reply to - as Mr. Morgan <salutes> has correctly pointed out, an account can be recalled at any time - there is no "statute of limitation" for account recalls.
The original owner or anyone with enough information can call Blizzard up and say "I was hacked" and if they can prove that they have enough information (SQ/SA, CD Key, Address and ID if needed) they can have the account reverted into their possession.
I suggest two things:
1) If you have enough information on the account, after it has been recalled feel free to try and recall it back. At worst they refuse, at best they lock the account pending a notarized document (can be a PITA to arrange) or even ban it. Okay, you don't get the account back but at least they can't use it...
2) Keep every bit of information you acquired during every single trade somewhere safe. I had an account recalled over a year after acquiring it. I know I stood no chance of getting my money or the account back but I did send a recorded delivery to the Mother of the guy I traded with (I had his address) which included the correspondance with her son and print outs of PayPal etc along with mentioning on the letter that the same information had been send to the local authorities. Will it work? Probably not, but I know I've done what I can and maybe the culprit will get a spanked bottom and sent to bed without supper...
I hope this helps a bit?
Cheers,
Del