You have probably never had to deal with a loved one with dementia, as I have. That woman could have forgotten that she hadn't paid for the items, something that could easily happen to someone with severely impaired short-term memory.
I read (I forget where) that she offered to pay for the items but Walmart told her to just to leave them (I don’t know if they stopped her as she was leaving the store or outside of it). She returned them but Walmart called the police anyway. Either way she did not have any items on her when the police treated her like a rodeo calf.
Here is a link to a Denver Post article.
https://www.denverpost.com/2021/04/26/karen-garner-booking-video-loveland-police/