If the regulations are broadly the same as that proposed by Simpson some years ago they do not take account of fatigue and are not designed to do so, the commander of an aircraft is however not premitted to fly when fatigued.
It follows therefore that an airline cannot rely on the regulations as reasonable limits and it is up to the individual to decide himself what is reasonable and when he is fatigued. I suggest an email to the CP copy to your FOI should do the trick.