Only my opinion, but it looked like he was too low (possibly a missed "gate") at the top of the last manoeuvre and had insufficient altitude to pull out. It looks like he was pulling very hard at the end there, possibly having realised he was too low/too nose down. Possibly not recoverable.
I agree with Craven, it looks like he then pulled too hard, causing the stall symptoms, but I don't think that was the cause of the crash, he was already too low/fast/steep. Step back to the start of that last manoeuvre and not pulling up enough and there's the point it started to go wrong. It may have been possible to abort the manoeuvre up to the point where he commits nose low. After that it was all history.
Hadn't really thought about this one for a long time. Just my thoughts as you asked for them. So very sad to lose a good man.