I wonder how many people would have turned in that much cash if they knew they were legally in the clear. Not many, I'd guess.
I'd also imagine the money would come from the scammers. Not from the bank. If I write you a check for $95,000 and I don't have that much on my account, then it bounces and you don't get the money, right. We can conclude the scammy company paid for it and their advertisement how to make %95k in 3 weeks was actually pretty accurate.
Reminds me of that British ad company which sent out emails to millions of people promising $10,000 for the first to respond with their name, address, social security number, and bank details. One guy actually responded, and they went to visit him to hand over the $10k :)
I'm sure that many of us set personal values that are more or less progressive than society's moral foundations, and that's a reasonable reason to not keep the money. And donating $100k to charity does not necessarily mean it will go to a good cause. Not all charities materialize "good effect" on society with cash contributions, even if advertised. It may have helped a charity, but it could have also been swallowed away into beauracracy. It doesn't make him a wuss to have returned the cash.