My first thought here is “wow, Brazil soccer fans are fucked up!” but when you think about it, I bet if referee were to suddenly stab Troy Polomalu in the middle of Heinz Field, pretty much the exact same thing would happen.
http://www.usatoday.com/story/sports/soccer/2013/07/06/soccer-referee-decapitated-brazil-stabbing-maranhao/2495199/
Soccer referee decapitated after stabbing player to death in Brazil
Police say enraged spectators invaded a football field, stoned the referee to death and quartered his body after he stabbed a player to death.