My son is now going through the same thing. His wife turned him in to CPS and after interviewing the children told my son that it looked like he was being set up. My DIL won't let him see the kids but the school after hours program called and told the DIL that she owed them money and she told them to get money from my son. He's not going to pay it unless his lawyer tells him to tomorrow.
Tiki
Please let your son know he is not alone! we are over a year into things, and hopefully see an end in sight. Will Freep mail you. We'll keep you in our prayers!