[D really did not expect his words to be taken like that, and there's an actual expression on his face in the form of an awkward slightly puzzled look as he tries to decide if he's obligated to do that.

He didn't say he would, but is what he said enough of an offer?]

I'll teach you, but not for free. This place doesn't run on money so you can work for it, pay me with your blood, or answer some questions.