None of us do. Yonks back there was a thread asking for posters to put forward what they believed happened. I think every poster said something different. Who knows, ONE of them may have been correct. As for the trial, he was convicted more on a balance of probabilities, than on one point in particular.
Again, we appear to be in agreement. I don't know if you meant here 'balance of probabilities' as a term of art, but I do think the case was not proved to the criminal standard. I base that opinion on the evidence the jury would have seen in 1986, to the extent that is available to us. And the position has only worsened for the prosecution since. On the basis of the 1986 evidence, he would lose a civil case, and had he been acquitted in the criminal trial, there's a fair chance he would have lost much of the estates in an inheritance action by the relatives; but he should have been acquitted by the jury in the criminal trial itself.