See, I don't agree with that. I think every citizen has a right to tell someone they think their language is offensive, just like every citizen has a right to use profane language (no matter how stupid or trashy it makes them look). Freedom of speech goes both ways. My dad always tried not to swear in front of my mother and me (didn't always succeed but at least he tried), and if we were in public and someone was using very profane language he normally would interrupt them quietly and inform them he had his daughter with him. Normally that would shut them up, or at least tone it down a little. Of course, that was back in the 70's. Now, I would be afraid to do that for fear of being shot, but it still feel that kind of language is offensive to others. I think he was perfectly within his right to say something, either as an officer, or as a private citizen.
And, I also have been in Wal-mart (more times that I would like ) and honestly to hear something being said in the next aisle it would have to have been said pretty loudly. A lot I supposed would depend on the time of day, but if she was stocking up for a hurricane I'm betting she wasn't alone in the store.
I think she seemed trashy too, but I admit there are times I have slipped.