If you want to keep it keep it otherwise sell it back to him with a profit. There is 1000 of people doing this all the time when people forgett. PLEASE first you get 3 email before it expire then you still have a chanse a few weeks after and then it will go to domain auction and then just then it will go public. So i do not think he want that domain THAT much, tricky guy just ignore it.
If you have better plans for that domain well then keep it at all means. It's all yours just give him redirection for the mail. I've seen couple of people before freaking out after they let their domain expired and somebody else got it. If that domain is so important to them why let it expired?
If his story is true he will pay you what you are asking for, but if I were you I wouldn't ask for too much. Please keep us posted
yes i agree with you... if he manage to buy a domain then how come he dont know how to renew it... i am sure he is playing games or something... but remember you are the owner now and he want it back... so take advantage of it like.... you will not get this kind of chance again... ask him a big amount.... and remember dont accept paypal... accept egold or other none reversable payment... because i feel like that person could be a scammer....
I generally would ignore this sort of stuff. I have had emails, phone calls and even snail mail like this. If it really is the previous owner and the name isn't really earning worth it, sell it back at a nominal fee. It's hard to feel sorry in this day and age when you have an on-hold period of 15-45 days where the domain wouldn't work. Another 30 day in RGP. And yet another 5-6 in pendingdelete. They obviously weren't using the domain *that* much and it wasn't some mission critical thing.