Verbal Agreements about lent money for Bond?

Dad bonds out adult son. Son loses, goes to prison. Before going, bond money is returned to son, who gives it to Mom, ex-wife of Dad. Son says he had verbal agreement with Dad that they were "even" and that included the bond money (this was after a disagreement between dad and son).

Dad now claims he never said ANYTHING of the kind, and only bonded son out conditional that he get the money back. It's son's word against dad's. Dad wants his money.

Does son have any legal grounds to keep money? Can Dad sue mom and son and win? What is the law on verbal contracts with no witnesses if one claims it is not true?

They are binding--Based on what you say here, you could file suit against him (or at least threaten to do so) in small claims court or in regular court; filing in small claims court is easier and requires no attorney...you could try to collect all of the costs and damages that you suffered due to his behavior...