This question is not for myself but a friend.

My friend is super anxious about going to this counseling session with his ex. His child has been seeing a counselor and the counselor said she wanted to sit down with him and his ex, the counselor didn't say why. He said he assumes it has to do with talking about their child's progress.
He is very anxious to the point of feeling like he's going to vomit. He's afraid of getting ganged up on and verbally abused. Verbal/emotional abuse has been very common with his ex through their relationship and beyond. He said he's at his wits end because no one believes him when he talks about the abuse, because she always does it when no one is around. He wants to go to this session that was requested because it is for his child, but he asked if i would be on the phone with him while he's there just in case she starts the abuse so he can finally have someone know what he's been going through for such a long time.
My question, Is it legally wrong for him to have me on speakerphone while he's there? I don't want him to get in trouble.