Where in the Regs does it say that one can negotiate with a CAsA employee as to the interpretation of a particular Reg?
Where in the regs does it say I can't? You don't do something just because there is no rule to cover it. It is always best to talk to people you are dealing with in the course of your business in a civil manner rather than ignore them and hope you don't get caught. How the FOI deals with his superiors and the degree of micro-managing he receives from them is his business.
If a new FOI wanted something different, I could have simply made the departure time "approximate" or "recommended."
This was a very minor matter at the time and I don't know why some people are sweating on this. Of far more importance and worry was the day to day safe operation of the aircraft within the weather and VFR minimas without being over cautious and cancelling a flight unnecessarily and, of course, the profitability of the business.