With respect to the reference to "exceptional circumstances", perhaps that might be left at the captain's discretion?
I know little about IAA regulations.
Within the UK, there is adequeate provision for use of captain's deiscretion in exceptional circumstances. The danger is in providing the company with a little leeway without rostering on the assumption that captain's discretion will be exercised.
This, it seems to me, is what the company are demanding the right to do.
Occasionally, and only occasionally, a break from duty of eleven hours, at least ten of which must be available to a crew at the hotel is acceptable from the point of view of Flight Safety.
Any pilot repeatedly being rostered for such a duty is going to become fatigued very rapidly.
And if ten hours "rest" is to become available to the company as a matter of course (what defines "exceptional circumstances"?) and therefore (assuming an average case) a pilot will be at home for a maximum of nine hours, during which time he must chat with the kids, sort out his bank statement and phone bills, mow the lawn, talk to his wife, have a couple of meals AND get some sleep), the situation will very rapidly deteriorate to one where safety is quite seriously endangered.