I am more than a little puzzled by the approach of some here.
The basics of the accident are fairly clear from the AAIB's report. The final manoeuvre was entered from too low a height, at too low a speed and the engine was not delivering full power during the climb into the manoeuvre, for reasons unknown.
The pilot's background and overall experience suggests that he should have been well capable of recognising this was not going according to plan, both in position and available energy. Most of us would presume that would involve changing the plan, not continuing. It is why we try to have alternatives available in flying, to cater for the unusual/unexpected.
That the pilot did not abandon the manoeuvre seems to be either an indication of gross misjudgment of the physical situation or an indication of over confidence or 'press-on-itis' - under the pressure of being on display. Not the first of us to fall foul of these, and sadly highly unlikely to be the last. Those two have killed many pilots over the years and given many more of us bad frights. Unfortunately it appears the pilot cannot throw any more light on any of this.
The underlying root causes which led to those errors require more consideration and go much wider than just a series of cumulative errors by the pilot on the day, but the first level 'causes are clear.
Throwing in things like altimeter discrepancies seems to me simply an attempt at a smoke screen - interesting and well worth debate for future but surely quite irrelevant here, given the direction in which that error would have shown itself. As for the technical failures of maintenance and associated paperwork, while they are appalling and indicative of corner cutting, possibly for cost reasons, they are not germane to the accident per se.
I don't want to see this pilot pilloried for a disastrous series of errors, any one of which any of us might make (though I'd hope most would manage to spot the trend before the lost cause point!) but I don't believe it does the cause of flying and flying safety any good to be seen touting pointless excuses as a 'get-out'. That has happened too often before and as a result lessons are not properly learned.