What a load of tosh. There's always some do gooder that has to take issue with something. As for the imbecile who thought it was a can of soft drink, if you cannot be bothered to read a label on a can of drink that was presumably surrounded by other cans of beer, then I'd say that it's kind of your own fault.
Serves them right for having paid £2 for what they thought was a can of fizzy orange.!