He can't sue the guy. Anything under the guise of "Data Recovery" always comes with a clause that states that "Not all data is guaranteed to be recovered. Any and all data may be lost permanently, or could be damaged beyond usable recovery. The recoverer is not responsible for data lost or damaged during the process." This is basically a bullsh!t way to cover the repairman's *** . However, I'm uncertain as to why you didn't just keep the HDD if you knew it was good. It's not hard to install an IDE drive into a new computer at all. Just slip it into a static bag and presto. Good to go till you get the new box.
What you could do is get him if on paper it was stated that he would perform services that he obviously did not perform, and after multiple attempts you were still unable to have your agreement met. This will only work if you have a contractual agreement with him. Very few courts will honour verbal contracts.
More or less your best bet is just to get a .bsp and decompile it. It's a sketchy process, but it would at least give you something to continue with. I've used one that was designed for RtCW before to learn how to edit things in Radient, and what comes out is often a mess, or doesn't make sense. But it may be more successful for you since A)It's your product to begin with, and B) There may be another decompiler that apparently isn't 3rd party from the editor itself.
Best of luck to you Sine, but I think that you're quite out of luck if you intended to sue the guy.
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OSC Returns!!
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-=I'm the
wang of this here site, and it's
HUGE! So just imagine how big
I am.=-
1337Yectiwan
The OSC Empire
10 of 14 -- 27 Lives On