I, with others, think the discussion on here has been very reasonable (and having had a brief professional acquaintance with Sean I would be among the first to shout 'STOP' if wanton speculation was underway).
The drogue and scissor shackle malfunctions suggested by the CAA document are one thing, and I hope that the evidence that will be available from the seat itself will allow reasonably quick progress on that aspect of the investigation. The more puzzling aspect of this sad accident is why the ejection happened in the first place; photos of the aircraft on the line showed no evidence of anything which might cause a stationary ground ejection (such as a major fire) and I suspect it is this aspect which the BOI will find much slower to unpick.