I also have safe all around.
I don't see how the OP can say whether that runner retouched 3B or not since the Ump's head/cap is partially blocking the bag as the runner retreats to 2B. I wonder if a proper appeal was even made?
All other points made in this thread are valid as well.
It always kills me when leagues want to cheap out by only having one umpire & then expect him to see every freaking little thing when multiple runners are involved. Bases loaded & they expect you to see the catch & every single tag up!
I knew a team that made a habit of appealing every single runner on this type of situation & then they'd pitch a ***** if you didn't call someone out!