I know that at the school I work for if a student had spurs on their boots they would be asked to remove them, they are considered a weapon. If they argued with the principle, I can tell you they would be in for a dressing down like they had never had before! Plus their parents would be called and told about how disrespectful the child had been. If it happened again the child would most likely be expelled.
There is no exscuse for a disrespectful attitude.