b41 leads to a ripped keima. It was just awful, please forgive me.

I should have laddered with b69:O14:

Is at B14 better than at D14, though? I think that I tried to add a sequence where White connected under Blacks stone at B15.

Back to D14 ; B14 where Black has four liberties to White's three. First, White can't cut the stone at C13 because the cutter will get laddered to the edge. So the two stones inside would have to add liberties or indirectly prepare the cut with at B16. But against that move, simplest seems to be just connecting with at B13. Instead, trying to add liberties with at C18 lets Black play at B16 and White's liberty shortage continues while White runs out of eye space.

I have to say again, I feel very grateful for the lessons!! Especially as I feel like the slow kid in the class...

This shape has some variations in Kogo's Joseki Dictionary:
http://eidogo.com/#kjd:pdttmcdpqg

ETA: Assuming your opponent didn't diverge so early.

Yeah, I looked at Eidogo. But note in your link, this Joseki does not include a variation in which the 4-4 player extends to the second line, which was the continuation I asked about in my original question. And as I stated, I only found three games with such an extension when I searched at Eidogo. The lack of an entry in Kogo's Joseki Dictionary, which was included with my copy of Many Faces of Go (and maybe my copy of SmartGo?), is what led me astray in thinking that there existed a "refutation."