So the sign on the door says it opens at 5 a.m. At 5;05, the door is locked and the one visible employee looks at me, waiting outside, and scurries in back. Bear in mind that I'm dressed for my white-collar job, so I don't look like I'm going to rob the place or like I've been up all night to get lucky.
I call and ask whether the sign is wrong. Gal doesn't know: they'll open in 10 or 15 minutes, maybe. No guarantees. She refuses to give a reason why they can't open on time or why the sign would be wrong.
So the serious plan was to leave a customer standing outside the restaurant for half an hour past the posted opening. Because when you want fast food, an extra 30 minutes is nothing.