I could see where someones first reaction might be, omg, crazy man with axe, stop him
it wouldn't surprise me all that much, if some crazy obsessed fan did show up to an event like this, dressed up, and started killing people for real
so, ya, that probably would be my frist thought when I saw the guy, too
(though, I wouldn't think to attack him, atleast not until after he killed the first person, then I'd kick some axe, or run like hell, either way)