Brendan, I had little time to watch chess today, but large chunks of MC-Nepo games 1 and 2 were basically my viewing.
I tuned in just at the moment of the missed checkmate. I think it was mate in 3 only if White accepted the offered Qg5, and mate in 5 with best defense by White.
The highest evaluation during my game 1 watching was around +5, but White was only up by one pawn. The modern computers are so strong that their evaluations are often beyond my comprehension, and this was one of those cases. I saw the extra pawn and a significant White initiative, but could not visualize a winning line! In such instances I'm inclined to think the position is holdable with "tenacious D" (US musical reference), and that turned out to be the case.
I have to cut Ian some slack, because he played those AI Cup games
right after the final 4 games of the "Levitov Chess Week" rapid tournament in Amsterdam, which he won by a clear 2 points with 12.5/18! I believe he had to miss the Levitov closing ceremony.