Gathered members of the public had nothing to do with it. The cop could have used the tactic if it was only himself and the person filming. In fact, according to the article, there is no mention of anyone else being there.
Regardless, do you know anything about copyright law and how it actually works in court? I do. Anyone who does knows how absurd this is.
"The copyright holder is harmed in the eyes of the law by the violation of their exclusive rights."
They are not harmed financially unless it cuts into their sales because people are substituting this for listening to a purchased or otherwise monetized version.
https://www.copyright.gov/fair-use/more-info.html
"Effect of the use upon the potential market for or value of the copyrighted work: Here, courts review whether, and to what extent, the unlicensed use harms the existing or future market for the copyright owner’s original work. In assessing this factor, courts consider whether the use is hurting the current market for the original work (for example, by displacing sales of the original) and/or whether the use could cause substantial harm if it were to become widespread."
Seriously, you should ask an attorney who works in the field. The copyright owner is really not a party to this case, they'd have a huge uphill battle trying to even get a court to take such a case, and if they did, they'd lose. And why would they bother? They don't have a dog in this race, as they say.
