Bad judgement or not, a competent govn't should present a unified front. If they want to apologize, fine. Apologize. If they don't want to apologize and want to play hard ball, fine as well. Play hard ball. But be consistent about it. You canNOT keep changing your position back and forth 4 times in one night. That is chaos. That is the very definition of chaos. And everything scenario you listed is evidence for it.
Since when is Philippine government competent? Not even their own citizens will agree to that.
Actually, Philippine government's positions are fairly consistent -- 2nd and 4th draft. The diplomat just gave away something they shouldn't -- either they are not authorized, or they are not told why they cannot.
Plawolf's theory is that Philippine government order the hit on the fishing boat, hence they cannot admit to full investigation and punishment of those involved. I think the diplomats were not told of that fact because they are not the core member of the administration. This version of events, while incredible, is more likely to be true because no one send out negotiator without giving them authority to negotiate and what the bottom line is. But in this case they cannot tell the whole story to the negotiators because they are guilty.