the engine won on time. I had a +5 advantage
BTW, I also played a few games, 2400+ player on Lichess, I had no chance. My impression is that the claim by this author is correct. Or I am overrated :-)
It also is not clear to me they didn’t just stop playing once they had +5, letting the clock expire, seeing as the opponent has no feelings or expectation of fair play. The game is detectably over at that point.