A legal consult will pay for itself. It may cost several hundred dollars but could literally save you tens of thousands of dollars in avoiding legal fees later.
Even just threatening legal action has cost me $1000-2000 for things that were fairly straightforward and settled without actually going to court.
And sadly I've seen XAH's stance get less reasonable over time.
If he's getting legal advice, he might be advised to go after the fact that you have a part time job and argue that the financials should he based on how much you could earn in a full time position. An attorney can also help you prepare to respond to that.