OBR Rule 7.05 - Each runner including the batter-runner may, without liability to be put out, advance -- (h) - "One base, if a ball, pitched to the batter, or thrown by the pitcher from his position on the pitcher’s plate to a base to catch a runner, goes into a stand or a bench, or over or through a field fence or backstop. The ball is dead;"
R3 scores and R1 to second