The cop has no idea if someone is recording, video or even audio. They have no idea what the filmer's intentions are. They have no knowledge or awareness of how the person might edit, alter, or distribute the content.

It would be 'dim' for a claimant to suggest that the cop is participating in some kind of attempt to break copyright.

Rather, more obviously, the person doing the filming in public, without anyone's permission or awareness, just as any other filmmaker/documentarian, is unambiguously a party to some kind of production that ultimately may or may not violate copyright law.