I concur, to me I think it was a factor of a modified 1/4 clover and then an oblique pull through that meant that the normal gate height would probably have been too low. Normally a 1/4 clover would be from 90 degs from the crowdline but the position of Lancing and Lancing College make this difficult. That's always been my opinion of civilian authorised displays compared to military authorised displays - the military ones are 'set piece' and not for modification, whereas, the civilian displays can be modified as required by the pilot. I remember watching a very experienced ex-mil pilot put an extra roll in his display over-sea and he did not recover. The UK military PDA regime is far more restrictive and modification to the authorised 'full', 'rolling' and 'flat' displays is not allowed as far as I'm aware.
That's my theory, anyway. Don't think it will be G-loc or overstress looking at the numerous videos. If he lost his engine at the top of the vertical manoeuvre then he would have rolled out and then gone for a FL towards the field, if he lost the engine going downwards then he would have been at idle anyway. But, hey, here's hoping the AAIB release something soon to stop speculation and actually report facts - rather than our best guesses. Of course something could have gone wrong with the jet, but I don't see any significant evidence to support that.
I do think the CAA have been right to enforce the restrictions they have - I don"t see them as 'knee jerk' as some have opined.
Sorry if my speculation upsets anyone. I do know one of those killed and one who is seriously injured so I think I am within my moral rights to comment 1 week later.
LJ