"Auditing what they say privately" is begging the question. The parent's point is that the training of police officers should be public. No one is proposing that we record the police trainers when they go out for dinner with their family.
edit: or rather, to feel dystopia creep more from the idea of monitoring how police are taught to use surveillance technologies, than from the actual police use of surveillance technologies itself.
I think both are dystopian.
+ Police driving down the road with facial recognition devices scanning the faces of all the private individuals walking down the street and allowing them to pull up records on any of them.
One of these things is not like the other (and the second is a current reality!)