After my incident (detailed elsewhere in these comments), we followed up with a few agencies whether there was anything that could be done to make it less likely that innocent parties are traumatised in the future by the very system that purports to do the opposite. Raised it with a local member of government as well.

There is no recourse against "procedure". The closest option was to raise it with the Police's internal affairs, but were told that's specifically for officer misconduct. And, with the exception of one inflammatory bitch, the officers were all polite and friendly (as they rifled through and took my equipment).

There's no ... anything ... that caters to the misconduct of the system.

(It's not surprising to a disinterested observer, but the feeling of powerlessness against such an injustice made it surprising to me).