You wouldn't, but someone would. Cops get called all the time for out-of-the-ordinary things that you'd not even think of calling for.

Power failures, parked cars, loose animals, strange kids, balloons, weather, etc.

For a laugh I used to read the local paper which published a log of police calls, they were along the lines of "A dead racoon was reported on Oxbow Rd. When officers investigated they found it was a hat."

Loose animals can be a danger to traffic, and the police should be called.

I've done this when a horse had escaped from a field at the edge of a village.

And as unfortunate as it is, some people see black people running in their neighborhood as a danger to society and will call the police (or in some cases will just hunt them down and kill the person themselves https://www.justice.gov/opa/pr/federal-judge-sentences-three...)

Very poor flamebait...

In Spain people call the cops for seemingly everything. I had a bunch of race motorcycles I was unloading at my house and some idiot neighbor called the cops because they thought I was running an illegal repair shop. I had to spend almost an hour proving that my four kids raced semi-professionally. Even had to show them their race licenses before they realized that I was telling the truth. I have found in many places in Europe people have a very hard time minding their own business — especially old ladies. For reference, I’m a white American. So some Croatians calling the cops after seeing a black dude doing a Forest Gump in the middle of nowhere would certainly attract the attention of the local busybodies.

This is schengen area border country, dealing with tons of smuggled immigrants, most of which are coming from Africa. While having from 0 to next to 0 local population of same/similar ethnicities.

First thing to many occur to especially older folks watching news is illegal immigrant running ie from busted police operation, not some epic runner. They definitely dont recognize running sportswear.

I mean, that is literally racism, the assumption about the man, based on his race, is that he is an illegal immigrant

Which other assumption would be reasonable, considering Croatia's ethnic structure? You have to take local circumstances into account.

But all of racism is based upon the idea of "reasonable assumptions". You don't need to assume. By your logic, stats can inform assumptions about black people being up to some crime, Arabs being up to some terror plot, Indians committing some rape, etc. etc. But the whole point is that one person should not be tarred by the assumptions others make about their ethnicity.

Your question is a trick. If only statistics make something reasonable, then the only "reasonable" assumption is that he is a criminal. And all racist assumptions will be "reasonable". But the very idea that a person should be assumed about based on his ethnicity is not reasonable or morally right.