How do you stop an ex from turning his son against his mother?

I have a friend, who is an excellent mother. But her ex-husband is brainwashing their son against her. The sole reason for this is that he is mad because he has to pay hefty child support (which is completely ridiculous since he didn't support his own son for three years). He is telling his seven year old son that he can't buy him things because he has to send Mommie $300 a week. He has also told his son that if Mommie touches him in any way, he is to tell his teacher immediately or he'll be in trouble. The kicker is that she doesn't even spank the child. As a result, children services has been brought in. The child told the social worker that he wants to live with Dad because he's "scared," but won't say what he's scared of.

My friend is scared and miserable about this. She is a loving and devoted mother who works, provides a beautiful home and is loving and affectionate toward her son. Her lawyer has advised her to keep a journal of what's going on. But what else can she do to stop this brainwashing before it gets worse. We live in Ohio by the way.