Ok, as a law abiding citizen, you might need to be sat down for this...
She told Dave (after she'd checked with her Sergeant) that because the messages had been blocked, they were no longer admissable - Dave shouldn't have been able to see them and therefore couldn't have been harassed.
Dave showed her the messages again, on the phone - there they were in full technicolour, but was told that he'd only read them because he'd chosen to look into the blocked messages folder - from the Police's view, they didn't exist as he'd blocked the number.
No further action.
Classic