You get what you pay for. And I doubt they paid. Cops get free food in just about every restaurant. I think it should be illegal. When I was a cop I turned it down and always paid. My sergeant taught me that.
However, any employee who yelled insults should be fired. Not necessarily for insulting a cop. But for insulting a customer...period.
When I was young and worked at a Starbucks I always would give cops free drip coffee. It really costs nothing.
They’d insist on paying. I would take their money and give most back so customers would see them paying. Soon I just took the money and put it in the tip jar while saying coffee’s free, and after a while they were fully trained and they no longer tried to pay.
Apparently they had to ask the chief if I could give them coffee, and he said yes as long as I distributed it equally.