That gets an incredulous scoff of bitter laughter before he can stop himself.
"Ungrateful? Oh, certainly not. No, I would never think you ungrateful. It must simply be your nature to express your gratitude by calling me no better than a brute and a whoremonger. 'I would not dare,' indeed. I would not wish to. I was a respectable officer of the law, once..."
The past tense hurts a little too much for him to keep going.