When I was 16, I worked at a fast food restaurant. During a rush one time, I accidently dropped a hamburger patty on the floor. I tried to cook a new one, but the manager saw me and made me put the dropped patty on the burger. I VERY reluctantly did so.

She was more worried about food cost and the customer's wait time. So, who knows, we all have probably eaten something that was dropped on the floor.

But I do have to say that in this case, that the barista was most certainly in the wrong, as was I back when I did that. I wonder what the barista's manager would have to say?