Which GM plays Rb8, a6, b5, and why play Kh8? Also, f6? And most of all Kd7. A 1800 Rapid player would have never played that! Surely not a GM. Even I would not. And why did he resign? He could have still won against this opponent. No GM would have ever resigned in that position.
So far, GM Simon Williams, as this game was based on his game against the chess ultra grandmaster computer. https://www.youtube.com/watch?v=BOPfOA6lVek&t= You can click on 9:45 to see the game. Except, instead of James Weasel committing suicide, he resigns. I think Simon believed that Rb8, and Kh8 would be good moves for a pawn storm, and for protecting his king, though I'm not sure if he made those blunders on purpose just for teaching purposes.
However, given the fact that it's a fictional game, not all moves would be 100% realistic or how a grandmaster in real life would play.
A GM with 50% accuracy?
That's what the stockfish analysis says. However, it's important not to trust the engine all the time for analysis. I already send the game to a few grandmasters in this site for any feedback for their own analysis to see if my analysis was wrong.
It is. I could have beaten John Weasel.
Correction: James Weasel. Also, there aren't any definite proof that it really weren't grandmaster moves. I still haven't received any replies from grandmasters yet, so we'll see.