Sometimes it is simply impossible to recover data if it has been mangled badly - large portions may be missing which might as well be the hold thing due to the way the security of a bitcoin wallet is structured. It's certainly worth a try to use recovery services in this situation, but it can cost a lot of money upfront for no guarantee of recovery. They might even recover the amount and sit on it for a few years before taking the money for themselves if they found out the true value - possibly destroying whatever is left of the original hardware to make sure no one else can get to it in future. He will definitely be kicking himself for years to come and hopefully makes peace with the loss.