Prosecution Confusion

I had a bad day, earlier this month, when I went to open a case at a South African police station. The shift commander claimed prosecutorial powers. He wasn't too articulate about it, but he summoned the legal officer to confirm it. Yes, she said, a shift commander had the authority to decide whether "we (the police) can prosecute or not". I said that was a mistake: there is a separation of police (SAPS) and prosecution (NPA), which is crucial. The police don't prosecute. Suddenly the shift commander denied that we had ever had this conversation. But I had it all in high quality digital stereo, which is usually the case when I enter potentially difficult situations -- it is legal in South Africa. I thought, which is worse? To claim prosecutorial powers, or to deny that you claimed prosecutorial powers? OBSERVATION: This is the second time police have told me this. What worries me is that I am quick enough to spot an issue of the separation of powers, and bold enough to say that I know what I heard. But what about the "humble people" who enter a police station and believe it? "Captain says there will be no prosecution." Alternatively, they are unable to prove that he said it, or they are too much in awe to express an opinion. This is the kind of hand-to-hand combat about basic principles which goes on in South Africa all the time.