As you said, I have never seen this blunder before. Now, if this happened at a Thoroughbred track say Saratoga, I could almost guarantee you the State Steward would be gone. I recall many years ago at Saratoga they reviewed a race and all three Stewards agreed and disqualified the wrong horse. All three were fired.
In racing, the Steward or Presiding Judge is the top dog. If it happens under his watch, he is responsible and must fall on his sword. But, in the world of C track harness racing, just another boo boo. On to the next race.