Gunn was accused of having illegally grabbed a security officer's arm in February 2023, after she was told with a camera-man to leave.
Her lawyer argued the touch was light and not intended to be hostile or confrontational.
The 65-year-old was convicted and discharged in November -- meaning there was no punitive aspect other than the conviction itself.
Today, a High Court judge ruled that was a miscarriage of justice, and the touch was acceptable physical contact, not assault.
