I never (nor would I) suggest Sol use the immigration ordeal (green card) to get even. That would be childish. I suggested she keep in firmly planted in her mind when her attny suggests they give in and hope for the best. Sol already went that route and her H did not hold up to his end of the deal. To think he will change his ways now is foolish. Just like D won't change his ways.
While it is a very series matter from a legal standpoint it also, as I mentioned above, exhibits a pattern of behavior. When such damaging patterns are established you can't go by a "wing and a prayer" and hope somehow this narcissist will start playing fair.
It's not about using the action against him. It's about using knowledge you have about his character to plan and execute a strategy.