The lab scenario fails because it makes no sense that there would be no alternative actions nor is the danger imminent.
When one says the danger is imminent, it is meant that a reasonable person could forsee that within a few minutes the danger could manifest.
Why “few minutes”? The time for the fuse to ignite a bomb can be large, but not large ENOUGH to find a way to stop the explosion. Of course, this is NOT the scenario I would suggest, it is merely an argument that the word “imminent” is undefined. I did NOT suggest the lab scenario.
Should a person who is not cognizant of his actions due to mental illness or some sort of substance intoxication be doing one of the above, then, altho their culpability would be reduced because they are mentally not right, one would still have the right to defend oneself, even if lethally. And one might even have the obligation to use potentially lethal force to protect another.
The good answer has finally arrived. Cheers!
You find a way to neutralize the danger without blowing up the neighborhood.
No one talks about blowing up the neighborhood. The problem is “what do you do if the only way to prevent to prevent the lethal danger is to apply lethal force”.
We did deal with it: we identified it as unrealistic and as invalidly attempting to force consequentialist morality.
Unrealistic, unlikely or not, it is a legitimate thought experiment. And you have no solution for it. By the way, the lethal defense against an intentional threat is ALSO a consequentialist concept. Looks like you STILL don’t understand. In a thought experiment ONLY the logically impossible states of affairs are disallowed; unlikely scenarios are allowed.
OK. We get it – an innocent person.
Yes. Innocent of any malice. But innocent people still can put others into lethal danger, unknowingly and unwillingly.
It depends on exactly what “puts” means.
That was the defense for Clinton.

What is “
IS”? It did not work then, it does not work now.
Let’s see. Just for the fun of it. This is only ONE example, nothing more.
A child (or an ignorant person) is playing with some dangerous materials, and is about to create a lethal substance. You are too far to intervene and if the final step in the process is allowed to occur, the lethal substance becomes reality. The
only solution is to grab a gun and kill that person to save millions of of others.
The child, or the ignorant person are free of malice, they are INNOCENT, they do not intend to put anyone into danger. Yet, their action puts others into danger. Can you offer a solution? Your only choices are “stay put” and allow the havoc on others (and yourself), or grab that gun and kill that innocent person. There is NO other possibility. No magic wand to be waved and no “deus ex machina”, like in the ancient Greek tragedies.