I think the move Rowson's referring to is move 9. Since in the essay he says "Yermolinsky offered a pawn as bait, and I very nearly didn’t take it because doing so would allow him to play a series of forcing moves"

So the only pawn that was offered and that Rowson took was on move 10 in reply.

The only reason I checked was to see how far a grandmaster was looking ahead, in this case 14 moves, which i find impressive. "...I discovered a surprising detail right at the end of the line, in which my knight could retreat back to its original square, "

Like you, I wouldn't be impressed if he only saw from move 18 to move 24.