First, I referred to JE's comment about the woman at the well, not the woman caught in adultery.  

Second, you clearly do not know the Law.  Adultery WAS a capital offense under the Law.  Hardly simply an act "a long way down the food chain".  But adultery involves more than one person.  Christ never condemned the proper application of punishment under the Law. In fact, he upheld the letter of the Law and condemned the actions of the woman caught in adultery in the only way He could under the Law; with words, not stones.  See, in the letter of the Law as righteously applied, there is mercy.   For the Law to be upheld {and remember, Christ was the fulfillment of the Law} BOTH the man and the woman needed to be convicted.  She wasn't "convicted" for masturbation, after all... 

Had BOTH the man and the woman been presented to him after a legitimate trial and conviction, His response would have been different.