LOL…

. Good to see you allow means other than murder now! You seek to persuade the carrier, he refuses, you now seek to compel, he resists, you use force, he uses force to resist. He is by this point a threat by his actions, not his mere existence. Could this lead to his death? Yes. Nothing new.
Obviously you did not pay a lot of attention. Please go back and read the OP again. It was very explicit:
if there is no other way to prevent the epidemic, is the use of lethal force allowed? The other posters said: NO, killing an innocent person is always forbidden. (and they tried to find loopholes to wiggle out of the dilemma.) The Apologist said: YES.
But your analysis still tries to twist the problem. There is no way to communicate with the virus carrier - for some reason. You cannot persuade him. He does not explicitly threaten with the disease. It is infected status which poses the threat, not his unwillingness to be quarantined.
Someone certainly is either pessimistic, or has a morbid sense of life.
No morbidity here. I just like to exercise my mind, and check out the “dusty corners” of morality. The good, old gray areas. Because they are interesting.
small question. Why not just isolate the disease carrier?
If possible, yes. It was also (implicitly) included in the OP
But the point was to explore the problem: “is the killing of an innocent (gotta love this word

) ever permissible?” Intentionally taking the life of someone “innocent” is considered murder, under any and all circumstances. No appeal to the “double effect”. There can be no exceptions.
It is “intrinsically” evil. Well, my “sicko” (but very logical) mind wanted to see if it is true, so I created this highly unlikely, but not impossible scenario, where the two principles (the other being “killing in self defense”) “collide”.
And according the Apologist, who is obviously far more qualified to decide the question (than you are), said that in some circumstances it is permissible. The conclusion is simple: “killing innocents is not ALWAYS forbidden, it is
NOT INTRINSICALLY evil”.
So what are we still talking about?