Great! That’s the best possible outcome
Error fares are great if the airline honours them. But the number of USA folk who sued the airline, or in the case of this ANA fare bought a ticket, but then refunded it to make a huge profit are putting the airlines in a difficult position.
You win some you lose some. But getting lawyered up over it is ridiculous. As are the charades in trying to call these fares anything but mistakes.
the only rule I fully subscribe to is to NOT call the airline until the fare is pulled. Calling the airline while the fare is live to ask for a seat number, or ask ‘is this a valid deal’ is selfish.