I agree with everything you've said. If that's all we've got it's difficult but that is still more than many cases. So we have go to other evidence from his earlier and later behaviour from which the judge has said inferences can be drawn.
If we couldn't nobody could ever be convicted cos nobody would reach that level of proof. Ever.
@bos posted a brilliant article above about plausibility and probability and what to look at to determine guilt. We only realistically have two options so which is most plausible?
That .article offers considerations for most plausible which states:
"a) which explains more of the evidence"
Both your.options are explained by just the park evidence.
So behaviour before and after? Which option best explains the rest.
Return to the park - after a rape highly risky IMO. He's not an idiot.
Go out prowling again after a rape - highly risky. She's likely to be found wandering around and distressed. Police will check. They'll be out looking.
Not admitting to sex after arrest - highly risky, she's only been missing 5 days at that point. It's now likely she's not alive and still likely she'd be found. Claim you had sex and left her ok somewhere is better than not saying it and risk explaining yourself after a body has been found.
@mrjitty had a term for the above but I can't find it.
"b) fits better with the fact finders beliefs and how the world usually works"
Explanation for return to the park is concern and to check she's ok. Is that likely given what we know about the way the world works. Would you reasonably expect concern from someone who's raped an extremely vulnerable person? Most of us cannot attack the vulnerable. In the real world it's unlikely someone lacking normal empathy would suddenly change to concern. So why go back?
His previous offences which have been allowed. Offences that are escalating and seem to show a liking for scaring woman. And his reasons for being out.
Pre planning shown by taking her there in the first place without obvious hesitation. The drone footage, prior visits. In the real world someone that plans even if just in theit heads, usually have an end point. The obvious end point to a crime is remove evidence - cos rape is serious..
"c) has parts that fit together coherently"
My opinion is that the above suggest the guilty option is more plausible and that that things fit together more coherently. The other option has incomplete plans, personality changes.