Am I missing something - ie I've not read anywhere that said what the aircraft was doing so where do we get it spun from??.
It would appear from the fairly intact airframe, the fact that it would appear to have been a low forward motion, flat contact with the ground, with enough force to fatally injure the pilots, that it may have been a flat spin. It could of course have been something entirely different, but the more probable cause COULD be a flat spin. Or a loss of control at low altitude, resulting in a stall/spin. The AAIB will confirm when all the facts are known, and the investigation is complete. Until then, discussion focuses on a probable spin in. I think that is where people are getting the spin bit from.