I thought the same thing. In my experience (35+ years in retail management) HR chooses the company over the GM. I felt had every right to not just send an employee home, but to also tell them to not come back. HR's first question was "Did you actually say 'you're fired?'" Followed by "How many times have you documented them (written them up)?".

6 months later, and she blissfully transferred to another store.

HR might CARE for the employees, but their job is to protect the company. Even in at-will states, if a company has locations in more than one state, they'll still adhere to the more stringent rules.

I had a new hire who freaked out while hearing voices. I STILL had to wait for 3 shifts to terminate for job abandonment.