Well the empirical evidence is that it cannot, as repeated rapid releases of this information sort of show.
Inability to follow the law is not a reason to ignore it. Should persistent criminals be ignored because they can't help breaking the law?
As to legality, I'm not sure if forward facing CCTV really constitutes privileged/sensitive information.
Please read the prior post I made, with chapter and verse on it. It is personal data, there is a requirement to control it.
Certainly on the level that would forbid defeat a release on public interest grounds.
Public curiosity is not the same as public interest. There is no public interest in something that has legislated appropriate and public investigation processes. If those bodies fail, a public interest and whistle blower argument could be a defence to a leak. Neither of those apply today.
Is there an expectation of privacy on a railway track? Certainly there is not on a railway station which is open to the public.
There's an expectation that personal data will not be released. That is the failure and breach of legislation here (again, see previous post).
I think it is highly likely to be no more privileged than a dash cam recording of a public road. The release of that sort of footage to news people on public interest grounds is common.
An individual with dash cam doesn't have to register with the data protection registrar. A genuine news source will often blank faces and number plates (again, see earlier post for links on personal data), and, largely, will know what is public interest and what is not.