So I don't know their situation or if it's a small cafe or big company cafe. If it's a small place, they could legitimately be out of some resource required to make coffee. I've been to several places where they make as much of what they sell as they can and once they sell out, they close for the day. I'm not saying it's efficient or anything, but some places like to run very minimalistically.
Also, the machines that make coffee don't just turn on and turn off, I'm pretty sure they need to be prepped both ways. They may have already shut off the machines and wouldn't be able to turn them back on in a reasonable amount of time. Should they have turned them off early? No. But again, from my experience with small mom & pop type places, their hours are inconsistent in that manner, sometimes they open a little late, sometimes they close a little early.
But these same shops tend to only be run by the owners and not random teenagers. So, probably just some employee who just didn't want to make a cup of coffee at the end of her shift.
My first job (aside from babysitting my cousins) paid above minimum wage, but I can see the issue from all sides now that I've calmed down.
Still, the thing that gets me the most is the fact that the place is a coffee shop. How does a coffee shop run out of coffee? O_o
If they actually grind the beans themselves or something, they may not have any ground up, they may not have any roasted yet, they could legitimately be out of coffee in general and need to stock up.
I don't know. I've been in those situations A LOT where the small places just don't get enough of all the ingredients they need. That includes cups, I can't tell you how many times I've gone to places and they tell me they are out of cups.