Well I cant answer your specific question HOWEVER, I would like this time to tell you (and remind the rest of you) about the BA JFK 6 (Possibly 7 now, but cant confirm that) who are under disciplinerary from BA as a result of going fatigued in JFK because after a long delay on ground with passengers onboard they were then put into a brothel of a hotel where they felt unsafe and unable to rest. BA are not disciplining them for going fatigued but for bringing the company into disripute (Cancelled flight etc).
All crew in the UK need to watch this case as it could have very serious consequences to the entire british crew community (and perhaps european community) regarding calling fatigue.