well it happens, quick story.. When I was about 19 (9 years ago) my band at the time was working on our second studio album. Independantly funded. The four of us had spent the better part of 70 hours each in studio and our producer and sound engineer double that.. When he was doing the final mix the computer crashed and we lost everything. Unfortunately these things happen. If you have no success recovering I would offer a reshoot. Most people should understand and if they dont, give them their money back and bid them farewell, you wouldnt want them as clients anyways
Wow that's horrible...it sounds worse than my situation..thanks for your feedback!