Random Effect Loophole
Take a gun and shoot someone dead from a moderate distance. All would agree this is an act murder, a violation of the sixth commandment and the criminal law of the land where they live. In a technical sense, what the killer did was to pull a trigger, which put a bullet on a random trajectory, which just happened to strike another person, who just happened to succumb to their wound, all as the outcome had the potential to be quite different. Nevertheless, the murderer fully intended to kill the victim and is morally and legally and halachically responsible, as this is not considered by any means a loophole to get away with murder.
I have heard of other situations in Halacha where loopholes of this fashion are exploited as a way to consider other ordinarily forbidden actions permissible. For example, there are electronic devices designed for Shabbat use that send random electric signals, all with the intention of making the visible result normal operation of a normal electrical device. How can that possibly be allowed when in the above example, it obviously isn’t?
Answers
Whilst I appreciate why the question is being asked, there is actually no Halachic comparison between the two examples. In the first case there is no Halachic leeway whatsoever. Deliberate murdering has no Halachic, moral or ethical justification. In the second case it is true that the Laws of Shabbos are sacrosanct but there are other completely valid Halachic dimensions that can be introduced into the equation that can change the way that the final Halacha will be defined. In your example there are two fundamental Halachos that are being added to the Laws of Shabbos. One is the Halacha of Pikuach Nefesh and/or Safek Pikuach Nefesh. The second Halacha is a concept called “Grama” and/or “Garmi”. The Halachos of Grama are too involved to go into in this forum but the basic premise is that a delay between the action and the consequence changes the Halachic definition of the action. It is important to point out that Grama and Garmi are not applicable in every single situation, it requires the Halachic authorities in each generation to investigate when they can, and when they cannot, be applied. In all events, there is nothing “random” about their application. They are very carefully modulated and used only within strictly defined Halachic parameters.
For a brief rundown of the concepts you might find the following shiur enlightening:
https://outorah.org/p/30000/
Best wishes from the AskTheRabbi.org Team