Patriarchy we pay for all this court and jury time - in the interests of justice. If we value it, then we have to pay for it.
It is the police's job to gather evidence and evaluate it so they can determine if a crime has been committed and who the evidence suggests is likely to be responsible. If there is concrete proof of an alibi for example so the suspect is not pursued, then that is not what I meant by 'screening evidence' = selectively providing or selectively disclosing evidence; it is presenting the gathered evidence and the evidence speaking for itself and there for anyone to see. There is a vast difference between evaluation and deliberately holding evidence back so a person cannot use it for their defence or to prove their case. .
The photos are not conclusive proof of his innocence or guilt of rape, and as you say we don't know the full details so it sounds like the photos should have been disclosed so they could be evaluated in court where the jury (and judge) could hear an explanation from both sides and take a view. If the discovery of the photos undermined the accuser's story so much so that it made her sound as if she were lying then that is another matter, but she should be questioned about it. And this can also be evaluated in court if there is any doubt.
Perhaps it is also the case that the mishandling by the police made them look unreliable and untrustworthy so the prosecution did not then go ahead for those reasons.
The senior CPS/ police person speaking on Radio 4 said that they do not routinely delve very deeply into people's lives. That sounds very worrying to me. We should be funding the police so that they can do their job properly.
I don't think we have anywhere near enough substantial detail to make informed decsions on who did or didn't do what, including police incompetence or wrongdoing, and that really worries me.