Unless that person is trying to go into a hospital, doctor's office, or some other place in the medical industry HIPAA doesn't do anything. It's like she heard the word at her doctor's office (probably because she had to sign something) and thought it was a free pass. People make me cringe sometimes.
I've said, I have no idea if a mask works or not (I tend to lean toward they do). But why wouldn't you just err on the side of "it probably does"? It's not like it hurts anything by wearing one and if it really does help, then all the better.
I was in Home Depot the other day buying the stuff for my garden. I was wearing my mask and minding my own business looking at the hot peppers. Some old guy gets way to close to me and not wanting to cause a fuss, I just moved away and waited for him to be done. He looked right at me and said: "you 🤬 Millenials will believe anything the media tells you." I was a bit confused and gave him a puzzled look. He then proceeded to tell me that I shouldn't be wearing a "scarf" because I look like an :censored:hole. I so wanted to roll out the "Ok boomer" line on him, but I just looked at him in amazement until he went away. Of course, I thought of a million witty comebacks the next morning in the shower.
Yes, it's your right to not wear a mask. It's also a store's right to deny you entry and tell you to get lost. Honestly, I wish all stores enforced the mask policy more, especially grocery stores because people would wise up real quick when they couldn't buy food because they were being pig-headed.