There's already been a few threads on this. Basically, he was the Olympic Champ. and Floyd was offered really good $$ by some Rademacher backers, so he took it. I think Rademacher was a pretty shrewd guy and knew he didn't want to be in the pro game for too long so went for the $$, knowing it would hurt is pro development.
today is the 60th anniversary i believe... i looked at fight details on boxrec. the fight was non televised and also not broadcast on closed circuit tv you had to be there to see it. boxrec says Rademacher put Patterson down in tbe 2nd but it was all Patterson after that, scoring 7 knockdowns