Sunamer, there was no intention to fly so low on the part of the pilot. That he did so was likely due to a miscalculation, the manoeuvre he flew was not a straight loop and this would lead to a reduction in the height achieved over the top and hence the lack of altitude to allow for a safe minimum altitude at pull out.
High performance aircraft are demanding to fly, the safety margins can be smaller than anticipated. In this case the investigation will be very thorough, AAIB are probably the best in the world at what they do. If changes are needed in display procedures and authorisations then they will be identified and made.