This topic became a landmine when conditions such as anxiety and behaviors such as hoarding became medically defined as disabilities.  

Newly divorced people tend to engage in reckless behavior like excess drinking, partying, "entertaining" guests that are mentally unstable, move jobs, etc.

You probably have no way to determine this, but maybe putting the warning out there will cause someone to change behavior. 

I don't mind helping someone out but what's happening here is Mom is milking her son, and by letting her continue to squat in this location he's enabling this poor behavior.

Very far.The lack of conscience and unprofessional behavior I find particularly galling. 

I have exhibited similar behavior in the past going to extreme lengths to convince someone they are wrong / I am right.  

It's a daily practice for me but it has built self-awareness and empathy.If you can see what others see in you then you can anticipate these negative feelings they are having and change your behavior and attitude to reflect the kind of person you want to see in the mirror.I try to treat all my employees with respect and give without expectation.

If they had an issue with the ACH processing again last night that would explain this behavior. 

Although I think something should be said for the sort of person who has a real estate license to engage in this behavior.

Hopefully it was an oversight, but even if your agreement (contract) saves you this time, I would be careful of the possibility that he could continue this type of behavior going forward.