I really need your help on this one, guys. I have a feeling there is no fix but here goes..

I had been running a vanilla server on my computer. After the server began to lag out, we copied the files to his computer. He used a torrent to forward the server through his computer while it was still registered on my computers IP. (we share a router) We did this for several days and the server ran smooth for everyone. One night I did a save-all on my computer and we shut down the server and his computer. When I turned his computer back on and loaded the server, I noticed all of that previous data was lost. (I believe to the point when we ran it through his comp). All of the recent logs are still saved on his computer, but I can't figure out a way to restore all of the lost data. I have a suspicion that saving it on my end and NOT his, caused the world to reset to my previous logs.

Do you know of anyway to fix this?