This is a perfect example of why the whistleblower needs to have the security of anonymity at the start of any process. It should be for the agency to whom the whistle is blown to carry out any necessary background checks and to their veracity.
The question of whether that person will be a witness down the line can indeed be answered down the line.
If whistleblowing is to succeed, it relies upon credibility, which in turn is founded on the validity of the evidence and the trustworthiness of the person disclosing it.
