Found this in En Passant magazine, April 1998, No. 149.
Berry stated that apparently Maurice Fox failed to deliver mate in 2 at move 44. (Tom O'Donnell: That is, 44... Qf2+ 45. Kh1 Qg2 (or 45... Qf1#)). (Maurice) Fox had thought Fischer had played the correct 44. Kh1 rather than the incorrect 44. Kg1. Maurice Fox had defective eyesite (so do I, it's a curse :) and this (to speculate) may have caused him to, at the board, play the game in the mind to a greater extent than does the typical player.