The Torah uses negative language to describe the method of punishment - death by active communal neglect or worse, by supporting those who would directly kill her. Estee Psaty has suggested that:
by using negative language as it does in phrasing the mitzvah, the Torah hints that the putative 'sin' of the witch is not outright deserving of punishment, thereby further suggesting that her death is viewed merely as a 'necessity'.
See, the problem is that she isn't really deserving of death - yet her death would be welcomed by those who think she (the one who is "bewitchingly" different) is a threat to the influence of those who control and hold power within the community. Consequently, she becomes a "marked woman".
Considering all this, it is clear then, that not only does the kabbalah have a built-in immune system, but also does Torah Law have a built-in immune system against those who would abuse it to justify manslaughter at best, murder at worst (should the witch die). Importantly, the "Jewishness" is questionable of any Jew who would blindly observe this mitzvah to allow harm to come to an innocent person by his or her active and knowledgeable neglect (or worse).
Why is the "Jewishness" of a Jew who blindly observes this mitzvah in doubt? Because, the truth is, the witch will not obviously die. And when she fails to die, she will eventually come to understand what the community has tried, yet failed, to accomplish - to indirectly, yet actively, kill her, abusing Torah Law to justify it.
The real sin done with respect to this mitzvah, is not one done by the witch, but by those who have turned the mitzvah into an idol, using it to justify participation in and/or facilitating the possible death of someone innocent (the witch not deserving of outright punishment) as opposed to using the mitzvah as a catalyst to discover his or her own "enlightened ignorance" in the active effort not to participate in or facilitate indirectly, yet actively, killing (or even harming) an innocent person just because a mitzvah seems to advocate it and G-d seems to have commanded it. A true child of Avraham and one with Torah in his or her innards would do the latter.
Without a doubt.
In Pursuit Of Ignorance