Two observations: You continue to claim that he KNEW his position was lost. At the "under 1200" rating you mentioned, very likely he did not, or felt that you did not have the ability to win in that situation. He was proved to be correct. The etiquette point is that even if he WAS simply playing out a lost position in hopes of ineptitude or a gross blunder, you needn't make such a fuss about, but should concede that he was--as he proved--right to feel he still had a good chance.
1. I can only say, with regards to the moves in the game (it's linked to a few pages ago), my opponent played very good moves... very quickly so I'm quite sure he was familiar with the endgame.
2. I have blocked other people in other platforms even as I've won games like that. I have resigned mate in 1 (in my favor) because I was disgusted with my opponent. I have purposefully stalemated a won game because I didn't want to mate my opponent because it took too long (6 moves) with at least 4 lines and I had 20 seconds in my clock and no increment. All of that means I don't care about that game. I just used it as an illustrative point.
Two observations: You continue to claim that he KNEW his position was lost. At the "under 1200" rating you mentioned, very likely he did not, or felt that you did not have the ability to win in that situation. He was proved to be correct. The etiquette point is that even if he WAS simply playing out a lost position in hopes of ineptitude or a gross blunder, you needn't make such a fuss about, but should concede that he was--as he proved--right to feel he still had a good chance.