On hearing of this accident my first questions were exactly as Distant Voice.
Why would such a risky drill be carried out whilst carrying someone who was without doubt a passenger (even though categorised as SC) on only their second flight in a Hawk, and why if that was to be the case was the PIC not flying from the rear seat, where command eject could be selected?
During my time as an engineer on Hawks at Chivenor this would never have been allowed. It would appear that the carrying of engineers on board should only be authorised on transit flights and not on any that impose additional risk to ground personnel who, not being pilots themselves, will have little or no situational awareness for which they are not trained. I get the strong feeling on reading the SI that the rules for the carrying of engineers on RAFAT have been allowed to erode to such an extent that they are almost considered to be aircrew -but of course they are not.