The graph on page 13 of the Ofgem report indicates that the initial drop in frequency was 0.16 Hz/s for 2.5 seconds. While this was greater than the 0.125 Hz/s of the old standard, it wasn't that much greater and was well below the 1 Hz/s of the new standard. Page 22 of the Ofgem report states that GTR have advised that it was the reduction in frequency below 49 Hz which led to the failure of their trains. The frequency was only below 49 Hz for 33 seconds (from 16:53:38 to 16:54:11) so it seems unlikely that many drivers would have attempted multiple reboots during this period. As it has long been understood that frequencies on the National Grid could drop as low as 47 Hz for short periods and other trainsets were not affected, this suggests that GTR (or the suppliers of their trains) have failed to provide sufficient resilience to rare events which lie within the Grid code.