20+ years of rc, 20yr chopper pilot, 6yr turbojet airline pilot.. All my aviation experience tells me: If you think you know it's an accelerated stall, you don't!!! Without some sort of a flight data recorder to tell you exactly what that plane was doing, it's all just guesses. I would personally trust a high time rc Jet pilot on what happened by looking at a video, over a full scale pilot anyday. We recover from them every 6 months in a sim, but the experts on what they look like are the rc guys.
IMO. No one should clame to know what happened, because the only fact here is, You Don't.