I have a question about slow pitch softball. The ump called a runner out at third, but then forget he did. A pitch was thrown, the batter got a hit and then the runner scored. When the next batter came to bat, the ump realized he made a mistake and he took the run off. He claimed this was a correctable error. My thought was since the pitcher throw a pitch, the last play was no longer correctable.

who is right?

Gotta go with the blue on this one. Since the ump called him out, there was no legal baserunner on the base. Hence, no run scored. They're just lucky that the runner on 3rd didn't draw a throw or interfere. Then, there would be a lot of rules to explain.

Absolutely correctable.