I've heard many stories of cops arresting persons for legalaly carrying with excuses of Brandishing, and treatening and some have no clue that an Indiana permit is good in Michigan
They also have a bit of a game if they suspect and you are in a public place of bump frisking you.
Michigan Attorney General opinion #7101 - Openly carrying a firearm does not constitute brandishing.
An officer who arrests you for OC or for brandishing should be charged with negligence and dereliction of duty (or at the very least, gross incompetence), in addition to being charged with a civil rights violation.