As an additional the second corroborator can be the accused themselves saying, 'yes that's me on the video'.
In the case from SRD it's possible the van driver abnd the passenger who took the photo could speak to the photo being genuine. That's why photos and videos on their own can't be 'evidence' as they are both easily manipulated.
Tapped into my other half's PF past again on this and she mentioned prosecuting shoplifters. You'd have the CCTV recording, and the security from the store would speak to that. You then needed the police coming along and essentially saying, "we turned up and that person over there was being held by store security and it's the same person as in the recording we believe", or the accused simply saying "it's a fair cop" (in which case you don't really need the video recording, though the recording may make it easier to get them to admit their guilt).
There are cases thrown out, or marked not proceeding, where there is only the CCTV recording, and one security guy. So videos taken by Joe Public such as me are likely to carry even less weight.
Or... What Dave said. I don't know enough about the Carloway review, but I do know someone who worked on it, so I may dig a bit further.