There are jurisdictions (and cultures) where truth is not an absolute defence against defamation. In other words, it's one thing to disclose the issue to the authorities, it's another to go to the press and trumpet it on the internet. The nail that sticks out gets hammered down.
Given that this is Malta in particular, the author probably wants to avoid going there for a bit. It's a country full of organized crime and corruption where people like him would end up with convenient accidents.
At least in the US there is a path of escalation. Usually if you have first contacted those who have authority over you then you're fine. There's exceptions in both directions; where you aren't fine or where you can skip that step. Government work is different. For example Snowden probably doesn't get whistleblower protection because he didn't first leak to Congress. It's arguable though but also IANAL