Long Night Shift Drama at Work

I work nights in a busy restaurant and things got complicated during my shift last week. My colleague, Sarah, was supposed to start right after me but she called in sick on the spot when I arrived to clock out. Since it's a small place with limited staff, our manager asked if I could stay an extra hour or two until another employee could come in. No big deal, especially since they've covered for me before during their shifts too. I stayed and ended up dealing with a large group of rowdy customers who wanted to argue over the bill and throw insults at each other all night long. Just when I thought it couldn't get worse, my shift ended and Sarah still hadn't shown up. The manager came looking for me as he was heading home and said he had no choice but to call a local UberEats guy, Tom, who's known to work odd hours too, to help out. Tom showed up just as the worst group left and things started calming down finally. I should have been happy to hand over my responsibilities, right? But there was an awkward moment where I felt bad since it wasn't fair that he got pulled in at such short notice. I mean, why me for this extra shift? I couldn't help but think about Sarah and how she could pull this on us again if we ever had a chance to talk it over properly. I know the place needs people to work, especially during those odd hours, and I'm usually okay with putting in extra time. It's just that last night felt like one too many instances where things didn't go as planned. So here I am, feeling a little resentful towards Sarah for not stepping up when she could have, and perhaps a bit guilty about how I handled everything on the job tonight. In retrospect, maybe it wasn’t fair to feel so annoyed since my manager was the one who really needed help with keeping things running smoothly.