You know other people have sat on the toilet before you, touched the doorknobs, pen on the credit card machine, soda machine buttons, pen at the doctor's sign in, ate at the table you are at, etc etc etc... If a baby in the cart is the worst I have to deal with today, then my day is looking up already.
I know you might be trying to bring something to someone's attention, but you said this happened a couple summers ago so why bring it up now instead of then?
Just curious