There's been some pretty harsh words said within this particular thread, but thank God that many of the respondants aren't on the Jury of any Board of Enquirey.
After such a very long duty day/night it's been my experience to be treated in a similar manner. Initial contact with crewing always commences low-key, but then gets ramped-up over the process of time. It's perhaps easier and less stressful to continue with an extended duty to another airport rather than trying to direct/organise a nightstop for pax/crew and aircraft. However, we all know that we are tired and that any further 'incident/accident' will lead to our own heads being put onto the chopping block, and it's those fears that are historically proven to be correct. Once that you commence to try and do any bargaining with crewing... you've lost the game; especially so within modern air operations that are steered by finance. Know the rules; and then act accordingly. If you've ben on duty for 24 hours... take 24 hours rest; however, you can't sleep twice in 24 hours, so you end up being just as knackered as the day before; except it's cumulative.
In conclusion, it's always going to be dangerous ground... especially on PPrune; where all of the 'experts' will judge you from the comfort of an armchair.
TCF