Reporting times is one of those chestnuts that raise their head every now and then. In the UK there have been many discussions at high level about reporting times at air side crew rooms. Are crew on duty before they pass though security or in some cases (long haul) check their bags in prior to going to the air side crew room? What's the definition of duty blah de blah.
In the end it boils down for either the airline to assess / manage or relies on crews good will as it has done for the last xx years.
Bit like me Office bod 0900-1730 probably done that a dozen times in 30+ years.
I could mention that Pilots are Managers (but possibly paid like Directors???) and once off the aircraft (albeit late) don't have to take too many worries back home with them whereas a lot of "Office types" do.....Mate of mine works in a commercial Dept for an airline has to make xxxxxxx $ a month or if not staff don't get paid or vultures circle.