Because that's the world I work in, professionally.
Just because nothing has been referred to the authorities doesn't mean there isn't merit to doing so.
If you steal a ream of paper at work and get caught, it's entirely likely that you get fired for cause, and the conpany doesn't deem it worthy of notifying the police.
Doesn't mean you didn't break the law.
If, instead, you stole $50 via wire fraud as a joke, you could also get fired for cause, but now you have committed a crime. Again, its entirely possible or even likely that the company not involve the police for a measely sum of $50....
See how there could be 2 separate infractions involving 2 different judicial branches (internal within the organization, and external with the police and courts) simultaneously, and that one deems referral to the other not necessary.