Agree that acquittal does not mean you automatically entitled to compensation, my understanding when going for malicious prosecution or wrongful conviction you need to prove beyond balance of probabilities that you have grounds for such damages- not that you were innocent. There lies the difficulty as the counter to such a civil charge is that there was evidence against you, or that the known evidence at the time of prosecution/conviction supported the case against you.
prior to 2013 you needed to prove innocence as I understand. The case of Roseanne Beckett set a new precedent removing the requirement to prove innocence in pursuing malicious prosecution, but it extended a bit further too, I'm no lawyer so I don't wish to attempt explaining it. (Might ask the missus later, shes one of those fancy law talkers).
my main point is that it was interesting how one court could acquit someone and another didn't automatically accept that as proof of innocence.