Abusers never change.
No matter what they say, what evidence they offer, they never change. Whether 22 or 62 they are the same. They learn nothing from their failures.
When they run out of victims they try to recycle. The abusive husband, older, alone, may appear mellowed. He may behave as the sweetest man who ever lived. Kind, helpful, almost without ego.
He strives to make his ex-wife believe, he has changed.
He is only playing this game to trick her. For Abusers never change. They may change tactics, but do not cease abuse.
The Boss From Hell, needing employees will call up a past victim, offering money and title and behaving ever so courtly.
If the past victim returns s/he will have maybe a month of normal before the evil begins anew.