He was damned if he didn't wish he had done it.
He might as well be hung for a sheep as a lamb, anyhow.

He broke off to curse Lord Loudwater at length.

He had been a curse to every one who came into contact with him while he was alive, and now he was getting people into trouble when he was dead.

Yes: he wished it had occurred to him to stick that knife into him.

He'd have done it like a shot, and he'd have done the right thing.