Neither do I condemn you to death under the Law, however, I don't condone your adultery so go and sin no more. Can't you see the difference.
In any case the Jews told Pilate that the sentence for blasphemy was death and that under the Roman occupation they weren't allowed to put Our Lord to death. Presumably under the same Roman Law they would not have been allowed to stone an adulteress to death in the street so the episode is more illustrative than actual. I read somewhere that the harsh punishments of the Old Testament had pretty much died out during the Our Lord's time on earth, so you are barking up the wrong tree here, Athair.