I think we are doing a disservice to Nik and the rest of us by a few folks assuming he stalled in his tight turn close to the ground. That is not necessarily true. As I posted several weeks ago, I have done some tests with my SS7 standard wing to explore this exact scenario but I was at 5000' for safety. Quoting my post:

"I have tried speeds from very slow to 90 mph and then suddenly pull hard elevator in a steep, 60 to 70 degrees, turn. I could not get it to do an accelerated stall. It would always whip around very quickly and lose speed quickly while the nose would drop and put me into a fairly steep spiral dive. Nothing I could do with elevator or rudder would keep the nose even close to level. It would spiral down, NOT stalled, and could be easily flown out of the spiral at any time. Now I am no test pilot and maybe there are ways to stall it in this kind of maneuver, but I could not do it. Bottom line to me, it seems like an extremely safe aircraft that wants to naturally keep itself flying. But I got to thinking about Nik's accident, where he appeared to make a very steep abrupt turn low to the ground. In this condition your nose WILL go down even if you are NOT stalled, and there may not be enough altitude to recover."

Let's wait for more info before we jump to conclusions.