I think its a little funny that people think Greinke is responsible for breaking his own collarbone.
You're out there in the heat of combat, trying to make effective pitches, thinking strategy, struggling to get guys out, and one gets away from you and hits the guy. I think Greinke's body language said "crap, I didn't want to do that, another guy on, is Skip going to take me out?".
And then big 6-3 240 lb. guy thinks back over the grudges he's held against this pitcher over the years and decides to mouth off. Grienke is already pissed off at himself and says "oh yeah, your mother too, butthead" and all of a sudden, he's confronted with a blitzing linebacker.
Not exactly the time to think "oh dear, what is the best way to handle this unfortunate situation? Golly, what shall I do?".