Can you explain to me how, exactly, one can "dodge" a broken arm? Keep in mind, this is a guy who is not only a good deal stronger than Jack, but he's also got a fairly good grip on Jack's arm, Jack leaned into it, and Jack is currently distracted by the fact that he just had a flipping chair swung at his face.

So yeah I think it's justifiable. Besides, Jack can just, like, tell Amaterasu that he wants to play a "heal my arm" game and if Amaterasu loses the sun will explode.