John F,
The report makes it clear that the speeds and heights he flew were fine for the JP which he had recently displayed. I find it easier to believe that he made a single cognitive error in loading his head with the JP numbers rather that he was trying to fly Hunter numbers and made a bog of it.
Logical but that still doesn't explain why:
1) Thrust was reduced during the manoeuvre - surely if full thrust is the order of the day in a Hunter, it certainly would be in a JP?
2) The manoeuvre was commenced much earlier than one might expect given the display area. Had the pull up been in the right place, would it have achieved 350kts by then - assuming full thrust applied? (I have no FJ experience so would be interested to know)
3) The aircraft ended up significantly off axis just prior to impact when you'd expect it to be on the A axis.