I was not a contributor to this survey ( I didn't know it had been run) but do find the results limited in their range of data.
To use a survey covering only 24 hour and a 48 hour periods of duty is not looking at all areas that contribute to Pilot fatigue.
I'm sure most reading both the survey and the posts here are well aware of the longer term fatigue induced by constant high hours per month, regular east/west long haul flights, back-of-the-clock flights, variable start and finish times, regular short periods free of duty and the list goes on. Arguably, it is this longer term fatigue that is more likely to lead to an 'operational event', particularly if a large proportion of a pilot group within an operation are subject to the same stress.
This is a start, but I would hope that a competent regulator would be looking at more than just this limited survey to recommend fatigue management changes and oversee the operators across the board.