I think this is a case where the reasonable person test is excellent. Is this use of a camera reasonable for personal/professional purposes
You should be expected to take reasonable steps not to victimise someone by use of a video camera, subject to public interest. That means filming strangers with intent to provoke them should be a crime but raging car park lady cannot reasonably claim to have been victimised. Consent affects what is reasonable without creating a duty-bound obligation not to film without consent.
We already have "reasonable expectations of privacy", why not flip that?