Apparently these are grandmaster level players being accused.
Your comment intrigued me, so I googled chess program strength. The impression that I got was that chess programs have gotten significantly better in just the past few years at evaluating the strength of a position, allowing them to be very aggressive in pruning the search tree.
This is pulled from wikipedia:
Chess engines continue to improve. In 2009 chess engines running on slower hardware have reached the grandmaster level. A mobile phone won a category 6 tournament with a performance rating 2898: chess engine Hiarcs 13 running inside Pocket Fritz 4 on the mobile phone HTC Touch HD won the Copa Mercosur tournament in Buenos Aires, Argentina with 9 wins and 1 draw on August 4–14, 2009. Pocket Fritz 4 searches fewer than 20,000 positions per second. This is in contrast to supercomputers such as Deep Blue that searched 200 million positions per second.