Maybe. The problem with a lot of stuff like that is that it's really hard to release information anonymously. The nature of the information is such that not many people would have had access to it, so for the assassins, the number of suspects is very low, and it's not that hard for them to figure out who did it.

I think the comment was making an analogy to a more contemporary issue.

As far as whether they could figure out how to target Koslov personally, that requires more info than we have. The nature of any complicated scheme is that, while yes, information is compartmentalized, doing it at all requires a lot more "regular people" than you expect. Leaders alone can't effect a criminal conspiracy.

At the end of the day, someone like, say, a mid-level foreign affairs analyst probably saw this stuff and could have blown the whistle too.

This is also true. In such a scenario probably an effective torture proof dead man switch (the one the whistleblower can't turn off once they kidnap him) could have helped. Something on the lines of "here's 500 pages of sensitive data in the wild about your crimes, if I or anyone of my family members disappear or die a thousand more pages will be published, and nobody can turn off this feature, including me".

I know I'm making this a lot easier than it really is...