I don't have time to go into the details, but mostly it seems quite okay as is, although the sources are mostly from US commentators. You might consult the editors who have done quite a good job with the article on the Finnish Civil War, which is well-sourced with primary Finnish sources.
As for why it is a thorny issue here: there are still a lot of high-ranked Finnish people from the Cold War era with all kinds of (past) connections to both the east and the west. The real historical scholarship on this topic starts only after the Finland-related KGB and CIA archives are opened, which might still take something like 50+ years.
