As long as no money changed hands, there is no problem.
Your Dad is not competent to sign a contract.
End of story, most likely.
It would cost money for the panel guy to file a lawsuit.
He is in business to make money - NOT to pay lawyer and court fees.
OK thanks, my stomach is in knots over this as he was scammed a couple of years ago out of a lot of money, and yes thank God he didn’t give them any this time.