Yeah, speaking as a bank employee, that mistake was a doozy. Great that the teller caught it, but oh, you really need to explain when you've caught mistakes so no one else thinks that catching the mistake was the mistake.

On the good side, it shouldn't affect your credit score at all. Savings and checking generally don't at all because they're not credit, but I suppose it's possible? In any case, the bank is the one reporting it so even if they've reported something as late, they'll just report it correctly the next time they check in. But still, it wasn't a credit account affected so you should be fine.