There is considerable case law regarding the free speech rights of public employees. As I understand it, they have the same rights as any other citizens regarding public issues. However, they may be disciplined for public criticism of internal matters, like a letter to the editor claiming the chief is incompetent. The quote in an earlier post citing Dershowitz' opinion seems to be on target. Where whistleblower protection fits in I just don't know. My uneducated guess is that the firefighters in this case were within their rights.
