I'm not clear on UK law, or the specifics of this case...
but how far can you go before you are found to be blatantly taking the piss? Isn't there some kind of "contempt of the whole f*cking nation" that can be brought up in order to get the beginning of an answer or face huge fines?
I mean, you can be thrown into jail for forgetting your encryption key, FFS! No "I'll get back to you about that" allowed.
(I do understand that the procedure by which the trove of docs was acquired is a step in the right direction, but it's very mild and not even directly targetted at the main defendant)