Regarding A Man of Kindness That Became A Criminal Because of Marital Discord

I recently heard about a friend (on the assumption the report is true) who ruined his empire of good deeds and kindness due to a fight with his spouse that turned him into a criminal.

What message should I take out of this shocking incident?

Our sages say “why was the parasha (torah section) of Sota (a woman who has to undergo an embarrassing test in the Temple due to a reasonable suspicion of adultery) put next to the parasha of Nazir? Because whoever sees the Sota in her disgrace should make a Nazirite vow to refrain from wine”.
In modern times, especially because we don’t have the Temple anymore, but also for additional reasons, our Rabbis believe it is a bad idea to become an actual Nazir, but we could look for alternatives to uphold the principle of doing strong acts to counter what we see are negative developments in our surroundings.
In light of this I am linking to a free 12 part audio series on a Torah perspective on Marriage.
I did not listen yet to most of the lectures, but am relying on the Rabbi who has a well known reputation as being terrific in the field of ethics and Mussar, that he knows his stuff.
The link is https://theshmuz.com/series/the-marriage-seminar/
Topics Discussed on the site include:

The Marriage Seminar: A 12 session, comprehensive guide, to a Torah perspective on Marriage.
A 12 session, comprehensive guide, to a Torah perspective on Marriage. The Match is Made in heaven; it’s up to you to make the marriage!

Why Do Some Marriages Thrive and Other’s Fail?

Love is the Glue that Holds It All Together
The Role of Physical Relations in a Marriage (This might be an eye-opener for many people)
Understanding Emotions — Yours and Your Spouse’s
Cycles in the Relationship-and how to react to them
His Needs, Her Needs — “Why in the world does she act that way?”
The Need to Change — “It’s not my fault; he pushes all my buttons.”
People Skills l — The Danger of Criticism, Complaints, and Carping
People Skills 2 —Avoiding Destructive Habits (Why do we fight over such petty things?)