The part where he called her a bitch didn't seem like a clue? It does to me.
Context is king, we need not assume anything about the relationship in the anecdote. It's completely irrelevant to the fact that AT&T failed in it's data protection requirements.
But NATURALLY, they're his kids because it was unspecified and you identify with the father, and because them being his kids makes her a bitch. Now it's internally consistent!
-- Anyway, I didn't say his used of "bitch" proved anything. But I've seen enough people in abusive relationships to know that it's a clue. The fact that he would illegally (and surely, contrary to company policy) abuse his position as an AT&T employee to stalk her further clarifies the picture.