Hello Beagle,
I am also very surprised that Capt. Brown has suggested that pilot error was the cause of this accident.
I'm not. I hesitate to speculate but I'm going to. First of all credentials: During my time in the Service I flew about 800 hours in Hunter T7/F6/FGA9.
From looking at the various videos of the tragedy is seems to me that the aircraft spent a few seconds in the back-side of the loop when there seemed to be little or no pitching going on. It appears that there was some flap down prior to impact. It is certainly seen to be down over the top of the manoeuvre. Why would he have used flap while inverted when the need is to unload to make the manoeuvre as round as possible? Using flap in the pull out is not only not necessary, it exposes the aircraft to the well-known Hunter flap-trap. His speed at the bottom of the manoeuvre would I guess have been in the order of 360-400kts, more than enough for the flap-trap to have seriously limited elevator authority.
The pause in the vertical suggests not only pilot re-adjustment of flight path but also raises the possibility of G-LOC, the insidious nature of which I posted about in the Gnat thread. AH, with whom I had a passing acquaintanceship, is a BA captain. On which fleet I don't know. If he is LH, when did he fly his last trip and was he still jet-lagged/fatigued? One thing I do know is that things which do not mix with flying FJs close to the ground are fatigue, hang-overs, the after effects of minor ailments and medication but the AAIB will no doubt be very interested in all that.