There are certainly trolls out there who could conjure such a story just for the heck of it, but I also believe there are people out there who would do this for real.
Also, some companies don't hire very often, so the seniority part is not the biggest red flag.
The fact that a concert was concidered more important than a graduation ceremony "because cost" might be the biggest red flag for me.
That was my gut reaction too. It's essentially a call center.
Also, I have a hard time believing that the type of person/manager that would handle a situation in such an inhumane manner (the sociopathic boss) would paint themselves in such an obvious bad light. Two different personality types.
It would have been slightly more believable if the girl (orphan?, dozens of foster homes, homeless, best employee by far, graduates against all odds by working nights, made-for-tv Lifetime Sepcial...) had written it.
Additionally it felt like a twist, I was waiting for this to be a mid-manager issue, where the mid manager didn't have the power to give the permission, not that they just decided to deny the two hour gap themselves and wanted them to apologize and come back.
Plus it says she's the employee with the lowest seniority, but worked 6 years there, that's hardly believable, the whole thing is hardly believable.