What if he was wearing the American Flag pin upside down, on purpose, indicating his patriotic concern that America is in trouble?
What if he was a citizen of Iraq, legally working in America, who wanted to wear the Iraqui flag as a symbol of his heritage, to assist guests in knowing where he came from?
What if he was a religious Muslim who wanted to wear the appropriate symbol to represent his deep respect for America's religious diversity?
What if he wanted to show he was really patriotic so he wore ten American flags (like restaurants where you wear lots of items of swag)?
What if he wanted to wear the Dixie flag to honor the historic base of the American south?
Does an employer have a right to stop any of these?