If I may be permitted to ask a question or two:
Based on my very limited experience as a 'breather', I've been told countless times that if the mask stops supplying air, you should either pull the green ring or drop the mask. In this case, is it unreasonable to expect that the pilot would have done the latter when he realised he was unable to reach/activate the emergency system? Or, would hypoxia have set in so quickly that he really only had one shot at pulling the ring?
If he had dropped his mask, would there have been sufficient oxygen in the cabin air (I note that there was cabin pressure failure) to have warded off the effects of hypoxia?
Not trying to second guess anyone, but keen to know what the alternatives might have been. One final one: are USAF AIBs expected to designate a *single* cause as the main reason for the mishap, or is there latitude for them to cite two or more main reasons?