The pilot was strapped in. He can do that himself if away from base by himself, but it was at Scampton so his mechanic would have helped him with the shoulder straps and anything else he requested. Seat firing handle pin must be in. It is everybody's responsibility to check the relevant seat pins are in place before they get into the seat, aircrew more so as they have to remove the pins and stow them from safe for parking to live (Safe for maintenance has recently been mentioned). As others have said, he would shut the canopy and remove the last pins to make his canopy MDC and Seat firing handle live. The SI report should have the statements of the liney as the main witness to the incident. I have handled Hawks before, on a VASS, so remember some of the pre flight checks requiring ground help, but cant remember if the pilot would show pins before stowing them (13 years has past). I do remember we were always instructed to move well away from the lid as it was being closed, in case MDC did fire off (like the Tornado). The lid was shut on the Hawk. The SI report will hopefully fill the missing holes in as much detail as it can. Seems some here have already seen the contents.