In the UK specifically, it would fall under the Data Protection Act. You need to make sure that the data (video) is used fairly and lawfully and for a defined purpose. In this case, the purpose of collection is safety, not for publishing on Bloomberg.com.

look up 2 party consent laws in California.

"Here in London..."

Not sure referring to California laws follows here. It's for a different reason.

that's for use of a recording in court, not sure it applies to this situation

What? No.

> The statute applies to "confidential communications" -- i.e., conversations in which one of the parties has an objectively reasonable expectation that no one is listening in or overhearing the conversation. See Flanagan v. Flanagan, 41 P.3d 575, 576-77, 578-82 (Cal. 2002). A California appellate court has ruled that this statute applies to the use of hidden video cameras to record conversations as well. See California v. Gibbons, 215 Cal. App. 3d 1204 (Cal Ct. App. 1989).

If there's a reasonable expectation of privacy, all parties must consent to the recording.