What a tale of woe
Some paranoid schizo buys a model rocket and some test tubes, Not really a threat to National Security or evidence of terrorism is it ? Evidence of dumbness ? It isn't illegal to be dumb or ill, yet, never mind.
Then he decides to keep his gob shut and not hand over some passwords, yes he probably did have something 'incriminating' on his p.c. No evidence yet of a issue, there are thousands of numptys, dipshits and assholes with hard drives bursting with stuff like this and guess what, not one of them will ever actually do a damn thing! Knowing how is no evidence of intent or ability or sufficient courage to DO.
So wipe the files, or destroy his p.c.'s, give him a warning and send him on his way, jobs a good 'un.
If he is ill suggest treatment, if he is a danger to himself or someone else the section him, happens every day to people like this, not really news, just a social problem.
Since the Judge reckons he's not a terrorist or threat to national security, then the ripa provisions do not apply and anything found could be argued to be inadmissible, He should get a good solicitor and media agent, set up a 'blog' and start an E-Petition like all the other fruitcakes.