so, there's this kid who rides my bus, and one of my friends is also friends with the dude. my friend kind of messes around with the kid, so i did i bit of the same. he tended to laugh at it a bit, cause it wasn't like name calling, i mean, we'd tell a racist joke or two, but it wasn't strictly on him, we did it to must people, even each other. we'd also say his name in like a funny way, nothing really discriminating, just in like a cuban accent(by the way, he's cuban). so, yesterday, this other guy on our bus, that morning had a poptart, and put it on the dudes head. now, the dude stabbed my friend in the arm first with a shank he made out of a pen, thinking it was him. then, in the afternoon, he try's to do the same to the kid that actually put the poptart on his head. the kid punches the dude in the face. now, they get off at the same stop, so on the poptart dudes way home, the cuban kid stabs him, with a knife, in the chest, and it punctures his lung. he's now in a lot of trouble. now, my friend says that us messing with him, isn't what caused it, but the counselor at our school says otherwise. anyway, i want to know, am i at fault here? did i pretty much stab the guy because i messed with this one kid just sort of joking with him? or do you think he was already messed up and just had bad anger issues? just as some more information, he has had some violent behavior before i even really met him.