No.
His only obligation is to defend you in court under the policy provisions.
You really have to ask?
You started the whole thing and you are in it to the finish.
What did you think would happen when you exposed a crook? Bad people don't stop at one bad thing. They keep doing bad things until somebody stops them.
Your obvious option is to tell him to stop and report the threat to the presiding judge, the newspaper, and any appropriate authorities that you can think of and open up another can of whup ass on him.
The threat to come after your mother may just be hot air. If you stand up to him and go public with his threat, he may back off and leave your mother alone figuring the publicity would be worse for him.
Up to you what you want to do.
The above is not legal advice.

