Hibs striker Derek Riordan had appeared to be bundled over by Steven Whittaker but referee Willie Collum waved play on.
"It's pointless talking about it, it's history, it's done and dusted. We can't do anything about it, so it's pointless talking about it."
Hughes also confirmed goalkeeper Graham Stack has been ruled out for the rest of the season with an eye injury.
Hughes said: "Stacky looks (like] he will be out for the season after he took a sore one on Friday at training in the eye; he might need a wee operation on that."