Law
The reason that Jan doubled down on his story was because he knew that if he was found out, the law could get involved. They could go after him for fraud and that would not be a good thing. But how many people were in on this scandal, if that were to be the case?
Maybe the journalist was wrong, maybe this was all just a miscommunication and the hospital made a mistake with their records? But that was the thing, the hospital never makes mistakes and he knew it. The law tried to launch another investigation into Jan and his family based on the new evidence.