I work for a retail store and a customer came to me, he wanted to buy a belt and he was wearing it and he had a barcode with it. I politely ask him to remove the belt so I can same the product code matching with the belt , he got very ratty and said ''come here this is stupid'! And pointed to the belt.
I think you where right in asking him to remove it as he shouldnt have pulled the barcode tag off to wear the belt without purchasing it first