Such is my folly
Dad, listen up a sec. With regards to the badmouthing, this child is 4 years old. The last thing he remembers tomorrow will be Mom made chicken but he didn't really like the crispy bits. You're already on a sour note because the reality is that it was mentioned only once, and 6 months ago. Already you're showing the GAL that you have a tendency to exaggerate. Saying that he cries because he doesn't want to go back with Mom is going to get you nowhere. If anything, it may work against you because in about 20 seconds flat, Mom can turn that right back at you and plead that the poor child gets confused and stressed every time he has to visit you. Then you accused an
officer of the court of being biased against you based on gender.
You take just these three things together - badmouthing-which-actually-only-happened-once, insisting that your 4 year old cries because he wants to stay with you, and the response you sent to the GAL - and you've just sent a message telling the court that you're inflexible, stubborn and are refusing to acknowledge your part in this.
The only reasonable option I can see is hightailing it to an attorney.... as in yesterday.