What concerns me, and I have not seen it specifically addressed, is that none of the three stated possible causes of this event come close to explaining being out of radio contact for an hour and a half.
Much is made of the fact of a safe landing at proper destination, but it seems that in this instance, it was sheer luck, not skill. I have seen no mention of the quantity of fuel on board upon landing.
Dialing the wrong frequency in the radio is a 'mistake'. Ignoring it for over an hour and a half is seemingly grounds for losing a license. Apparently it is now felt that a portion of this blame may spill over onto ATC for failure to notify the military in anywhere near a timely fashion.