I think I meant to answer your point on this earlier when I posted a very long response to
@Steve2021 listing mine
Surely the balance of probabilities is all we ever have in any trial. We're never going to have 100% certainty or even 99%.
That is why ALL explanations for ALL evidence has to be considered against other explanations. A trial has to look at everything.
So when we see PR put something in his car there is a probability it's Libby. That probability is raised by finding her watch and the previous CCTV of her and him on the road. So we're sure beyond reasonable doubt even tho there could still be doubt. She could have lost her watch before that night for example, in that exact spot, but it's less likely.
You have look at each piece because one piece - eg PRs car at the park - increases or decreases the probability of another piece. For example that he is the man seen walking away. If that man looked significantly different that would reduce that probability of it being PR to close up zero. But has it stands he doesn't look different
If you take the whole evening and try to find alternative explanations ,- adding in each piece of evidence I think on balance the alternatives fall down. That included every piece of evidence. His behaviour, his reason for being out, screams, his testimony. Everything.
That's my opinion based on everything we've heard here. Not my opinion from just one piece of evidence but on the probabilities of each one as a chain.
The jury will have more. They're better placed. They will also have a better idea of he how those will be interpreted to fit the law.
Just my opinions
Edited to state those are my opinions and how I looked at the case