Dirty shoes and no pizza

How disgusting is it to touch one's shoe in public?
Disgusting enough for the clerk at the 7-11 who refused to accept money from the woman who had just ordered a pizza slice.
As he was walking back to the cash register with her order, she put one of her shoes on the counter and rubbed it to try to clean it. The clerk looked at her, shrieked and refused to touch the bill she handed him at the same time.
"I'm not touching that money. No way."
She is about 25, a plum and short woman with pink tights and coordinated shoes.
Clearly, she thinks he is joking.
"How come you don't take my money? -- I want the pizza slice".
"I'm just not touching this!"
"But it's money! Money don't smell."
She keeps on insisting but he is relentless.
"It's disgusting-- that's what it is. You touched your shoe and then the money. It's disgusting. I'm not touching it. I'm serious." He is looking at us, the others customers for the tiniest sign of approval.
She decides to leave, changes her mind at the door and comes back to say "I'll call the police. You refused my money. I'll get the police." Her friends are around her, trying to calm her down. I get my paper and get out of the store only to be trapped under the canopy by one of these summer thunderstorms. It's too violent to last and everyone is waiting for the rain to stop.
The woman comes out with her friends. They're standing right next to me. Her boyfriend is holding her tight "Let it go, baby" he murmurs "it's not worth it."
She is still outraged. Dirty shoes and no pizza.