"...not to cause alarm..."
Vague law is vague. Any half way decent lawyer can argue his way out of that one. Seriously.
How do you determine if someone will be/was/is alarmed? Is there a definition for "alarmed." If I were an LEO, could I say that carrying a long gun on your back, muzzle in the air could be alarming? If there were ever a law that needs legal precedent, this is it...