Its been many years since I have had anything to do with gliding. Just not my thing to hang around all day helping out on the strip to get my "turn" in one of the club's gliders. However, I used to aero-tow a bit for them and solo'd in the Blanik as part of my training for that approval.
“this accident was the responsibility of all in general and of no one in particular.”
While a terrible tragedy for all concerned, I think the coroner got it right! Who are you going to blame, the poor "wingman" who gave the "go" for the TO probably without realising that a glider could be on final out of sight behind the trees, or whoever approved the strip for gliding ops, or the Nimbus pilot who didn't see the Blanik or wasn't able to dodge it, or whoever didn't ensure that comms were in place with all aircraft operating in the area.
I flew GA for a number of years out of one of the busiest weekend gliding clubs around. I don't recall any serious incidents. The club had a couple of highly experienced CFI's in that time and, as I recall it, an enviable safety record.
Dr 