The Honest Guides YouTube channel has a video on this with Czech ATMs. It was showing how there would be lower fees if one accepted DCC. Also, if you used a local card, the default denominations offered were far more reasonable than if you used a non-local card. It was always possible to withdraw a lower amount, but you had to bypass all of the default options.

I would have taken exception with the person who deliberately pressed the DCC button on that one transaction. Even with a small amount, I'd pursue a full chargeback on principle.