We don't have the "fruit of the poisonous tree" doctrine in the UK.
I didn't think so. That's the question I was interested in exploring.
The U.S. doctrine of searches, search warrants and the whole jurisprudence around the Fourth Amendment derive from the bad experience the American colonists had with Great Britain's "general warrants." Hence it does not surprise me that American practice is considerably narrower. Nevertheless there are curable defects for searches in U.S. law as well. When a public defender wins a motion to suppress evidence, it's still a matter for celebration.
In this case, if I understood the summary on TV (so, plenty of scope for misinformation and misunderstanding!) the police applied for warrants under two bases, one was correct and one was incorrect; the CPS approved the incorrect one.
I'm still hoping to understand how the two sections of law work together. Section 9 seems to presume activity also under Section 8. Sadly my spouse is no help, not being a U.K. attorney and generally taking the position, "Didn't we fight a war so that I don't have to know this?"
The way I read the law, Section 9 cannot be invoked separately from Section 8 as a basis for obtaining a search warrant. The way I read it, Section 9 applies as an exception to Section 8 when privileged material is the target of the search. An extra showing before the magistrate is required in addition to the showing under Section 8. If an application is made under both sections in the hope of seizing privileged material, but someone deems the Section 9 portion unnecessary (i.e., the evidence to be seized is not believed to be excluded or privileged), then I can see how a court might later determine that a Section 9 application had in fact been required.
In the U.S., a warrant is issued simply upon the sworn declaration of an officer. If the declaration alleges sufficient cause upon sufficient facts, the magistrate grants the warrant. If the warrant is deficient only in inconsequential particulars but otherwise in good faith, then the evidence obtained may still be admissible. But for example if the allegations in the warrant were knowingly false or misleading, then the defect in the warrant is not curable and the "fruits" of the search are inadmissible.
The only exception to privilege under U.S. law is the so-called crime-fraud exception. Overcoming the presumption of privilege may occur when there is other evidence that the privilege is being used to hide evidence of crimes or fraud jointly perpetrated by the parties to the privilege. When so alleged and supported by fact, the magistrate rules prior to the search that the material is not validly privileged and may be seized.
I'm not sure what TAFKAP hopes to gain from the legal action, since I think that what ensued from the search is still valid.
If there is little to no chance that the legal posture of the warrant will result in suppressing evidence, then I don't see the point either. A criminal defendant is entitled to a vigorous defense. But I don't see how this situation would resolve for Andrew as it might under U.S. evidence law.