it used to be
Still is in some cases, though there are some discussions about decriminalising it completely. It's nonsense that it can be seen as a criminal rather than civil matter.
but they had to call the police which usually makes the fee higher - much higher so you didn't pay that much.
Getting the police involved is actually a wise idea, because there's no guarantee that they're genuine inspectors. At least in Poznań and Wrocław, there's no additional fee for doing so, and from what I remember, there were issues in Berlin with fake inspectors.