What does “For all his cunning” mean?

Question

The doctor has just left me. At last I have got at something definite! For all his cunning, he had to speak out at last. Yes, I am soon, very soon, to die. The frozen rivers will break up, and with the last snow I shall, most likely, swim away ... whither? God knows! To the ocean too.

These are first few lines from Ivan Turgenev's story, "The Diary of a Superfluous Man". What does "For all his cunning" mean here?

The Diary of a Superfluous Man

Answer 1

For all X is equivalent to despite X, but somewhat stronger: the all implies that X is quite substantial, and the action of the main clause is therefore all the more surprising or (as here) triumphant.

Answer 2

The meaning of "for all his cunning" is despite his cleverness. The doctor wanted to avoid talking about the man's near death. But the man got the truth out of him.