Your points about the syntax are very interesting. Will try to weigh in later today.
One comment: I think that is the only way clinton talks, i.e., he uses the pronoun "I" when he wants to arrogate the achievements of others as his own, and "they" when he wants to blame others for his failures. In the gray areas, he uses "we."
That is why, on the surface, it is a bit surprising that he stated flatly, "I failed."
But as I pointed out above, (1) that he failed is self-evident so he is offering nothing new and (2) the admission, "I tried to kill bin Laden and I failed" is the most innocuous explanation of the failure. He and his wife will never survive the real reasons for that failure.
This admission is against type and should rouse the suspicion of every investigative reporter that there is something bigger here. But it won't.