I will eat Chic-Fil-a a couple times a year.
I worked fast food all through high school... most of the food was insanely poor quality and I remember most of the people I worked with "washed" their hands by just dipping their hands in the sanitizer water that had all the rags we used to wipe down the tables.
I never saw anything super gross happen to someone's food (no spitting in the food/dropping then serving it), but expiration dates never mattered and we were taught not to give a fuck about anyone's food, especially if they were in the drive thru, because "Fuck it. Dude, they're not coming back to complain."
One gross thing was that someone managed to throw up in the freezer once a year. One time, the dude threw up, left it there, and then some poor girl had to chisel that shit off the floor the next day.
The worst was when this crazy ass chick Marissa got sick in the middle of the shift. I was on drive thru and she was on front counter during the lunch rush. Something was wrong with her in general, but this day she was taking orders/serving people with one hand in her pants. Everyone she handed the food to wasn't sure whether they should take it or if they should complain. Eventually, she started throwing up in the small trash can in my drive thru area. It was disgusting. I'm not sure what happened after she started throwing up. I just took my headset off, clocked out, and drove off.
My favorite manager was a 45 year old dude who used to blow coke in his truck on his breaks and his mistress would come visit him at work. Sometimes he would come back inside with coke all over his face. He was always good to us and treated us with respect. He was a train wreck of a dude, but a great manager.