From the looks of it I thought you were flying, Jacko...
From the descriptions and photos, it looked a lot like a repeat of the Flanker at Paris in 1999, the crucial difference being that the Flanker zeroed its descent rate at a small but crucial negative AGL. (If you remember, they wiped out the tail but managed to force the damaged aircraft up to a point where they could eject.)
The following applies if there was nothing wrong with the aircraft...
The lesson is that when pointed downhill at a few hundred knots, without a lot of lift on them, fighters accelerate really, really fast. Whether you are too low or too fast at the top of that kind of descending manoeuvre, or don't pull hard or early enough, or whatever, it doesn't take much to eat that 100 feet that you planned to have left at the bottom. And you can find yourself very quickly in one of those embarrassing ye-canna-alter-the-laws-of-physics-Jim situations...
It's also an unnatural act; it's not the way fighters are flown at high speed near the ground. It's not something that operational pilots are trained to do.
And before we jump in and say "screwed the pooch", look at the EF pilot-vehicle interface and the impact of carefee handling. Does it lead to disconnection and over-confidence? Are there any "why'd it do that?" issues (like early Airbus experience, remember Mulhouse)? Did the computer understand what the pilot was trying to do? (Mulhouse again.)
Is it good judgment on the part of BAE or the RAF to have an operational pilot demo the aircraft in that scenario? Fort Worth has long had a cadre of demo pilots who are specialists within the company test pilot force. If anyone can recall any mishap, or even any of that group getting spanked for busting minima, let me know.
Interesting aside: I wonder how important the vertical component of the thrust was in maintaining the positive AGL? With the alpha he had on he was almost like a Harrier in STO mode...
Further to the physics issue, I was reminded of this:
http://www.pioneer.net/~fitzrr/zell.jpg