Granted, there's far less than a smoking gun in the RCF reports. But a dead body of a homosexual reporting of sex abuse and homosexual conspiracies in the Church - right before that relevant testimony is about to be delivered to church authorities - is not exactly a rumor or innuendo. Determining why such a person may have been executed is a legitimate topic for investigations by journalists, law enforcement, and concerned Catholics.
According to the article, Callaghan and Adema were private investigators, i.e., no police powers.