> It might be 'racism' of the sort that everybody is desperately searching for in every nook and cranny to hang their ideologies on
It seems to me as though you're looking in every nook and cranny to find people doing this!
I wasn't there, so I don't know if it was racism. But the author's inclusion communicated to me that the police officer was racist. The author could have made that more clear by writing "[racial epithet]" rather than "[ethnic group]" but following the principle of charity makes me think the author found it relevant, and I think we agree that that shows the author thought the officer was racist.
If the officer had just said "black gangs" or "Mexican gangs" or something like that, then maybe the author read too much into it. But the author was the one that was there, and who heard everything else the officer said, and clearly thought that the racial bit was worth communicating. So why automatically dismiss that?