It's a legally grey area. In most countries, you can't really stop people from shooting video and photos in public spaces. But you can do something about publishing the material. Most stock photography websites and similar websites will insist on permission from identifiable individuals in photos or videos for this reason. And a lot of conferences or fairs will give notice of the fact that there will be photos and videos taken at such events (thus clearly marking them as public events). I've seen that here in Germany at least.
And this is a sensitive topic here. Some people here get upset if you point a camera at them and will aggressively demand that you delete their photo. I've seen that happen a few times (not to me). Some people really get pissed off over this here and they tend to known their rights. So good luck arguing otherwise.
If you look at the rules here, they are quite sensible. You can't just publish photos or videos with recognizable people in them unless it's clearly a public event (like a demonstration, concert, etc.). Taking the photos is mostly OK (up to a point). And there's an exemption for private photos. But you can't just publish photos with people recognizably in them unless falls under the narrow set of exceptions to that rule.
Photos of people actually count as personally identifiable information under GDPR. So, people can object to that being stored by companies, ask for it to be removed, and companies need valid reasons for storing such photos.
In this case, the person is in the UK where people simply have less protections against this. Which is something the tabloid press there tends to abuse by trying to get photos of famous people in private / embarrassing situations by all means possible. That would be a lot less legal in Germany and expose you to lawsuits if you were to do that. The German tabloid press has a rich history of that happening.