It seems that the jury had to acquit him given that the judge told them that Mr Hill couldn't be held criminally responsible if he was suffering "cognitive impairment" ( presumably g-induced blackout )
Given that it was impossible to prove that one way or the other, they had to acquit. "Beyond reasonable doubt" for a criminal trial.
I suppose it now passes to an inquest, which doesn't have to satisfy the same criteria or find criminal intent.