If Jason and Victor were not there, no violence would have occurred. Marco had it coming to him, as soon as Jason went up for eviction before he did.
Any problems Emma, Michelle, Nadia, Marco, Vanessa, Shell, Stuart, Ahmed and Daniel would have ever had would have been resolved with words.
Victor and Jason only know how to let out their anger is by lifting their fists - they are a danger to everyone in there.
If they didn't play the game SO SERIOUSLY they would not have been so angry.
Saying that, the one who should take the most blame is Endemol.