Alot of the things pigskins have said will happen have happened. The fighting, the drinking, and the out of control parents.
Ted, this is sounding like a personal vendetta with you. One person posting something on a website meant for complaints means nothing to me. People use that website just like this one to ruin people's reputations. I don't know the man but, I would be careful if I were you, there are no charges on this man's record that indicate he would harm a child in any way. He passed a background check, as stated before. If it's your opinion that's fine, but initially you came on here and said they all look shady but now you keep zeroing in on one man.
BTW, I highly doubt there would be any repercussions toward your nephew, but there may be some against this man's family now that you did this.