BV,
I totally agree with all that you state. I would like to add that there is no way that a "check out" in a JP should qualify one to fly a Hunter.
Any pilot who is disciplined and professional who performs aerobatics (at any height, let alone low level) sets and learns gate heights and speeds for the whole display. They are written on a knee board and if low level engraved on ones mind. Even if one was suffering from the effects of "hypoxia" these numbers would be almost the last to go from ones memory. As stated previously, a fast jet pilot is trained so that his/her mind can still prioritise even when operating under duress. Operating under g forces, the effects of, and how to counter them were all taught in the RAF since the Meteor. Just because the USAF discovered gLoc in the late 70s and we learnt from them does not mean that there was not such training previously.
Is it possible that the supposed "hypoxia" was caused by hyperventilation due to anxiety. Was AH over-breathing and thus filling his lungs with Carbon Dioxide? Was he dumped with the Shoreham display (a difficult venue for a fast jet) at a late stage and he was not able to say No. The downwind takeoff and track taken prior to the display are not necessarily the actions of one in total control! Even so, if properly trained and qualified he should have been able to over come the situation that he put himself in. The accident was avoidable!