Generally it's worth talking to a lawyer about cases like this.
"The clinic has been sold to new owners. They are reviewing finances and rescinded any job offers, including yours. They will allow you 30 days to repay your relocation assistance."
Oh hell no. He lawyered up. He'd sold his home. Wrapped up his, and his family's life. Had an offer and a contract.
He didn't end up repaying his relocation assistance. And his "new" "employer" ended up paying three months salary and the closing costs on his house for the inconvenience.
A pittance because now wtf is he supposed to do?