Blocks To The Past

At 15-15, Carmen and her partner eventually won a long point. For the next point, the server on the opposing team called the score as 30-15 and then served a fault. Carmen realized the error and said it should have been 15-30. The opponent said that since the score wasn’t corrected before the serve, the score stood.

What should happen?

The opponent was correct, and the score of 30-15 stands.

The score should return to 15-15 since that was the last score everyone agreed upon.

The score should be 15-30, and the server should get another first serve.

The game should start over at 0-0.