However if you're in a plane nose-diving vertically, shooting someone a second before the plane hits the ground (in a way that obviously is going to kill everyone), hardly has any moral relevancy. It's taking 1s of life from someone, probably comparable to smoking a cig near someone. More so, this is a low-quality second of life, with all the stress coming from the awareness of imminent death.

So the argument still stands, the difference in the consequences, when considered outside of any context, is simply not worth the mental effort to figure out if the lever should be pulled. The exercise is only interesting because it provokes to think about real life scenarios.

Right but if you ask someone whether that situation is murder I bet most people would say yes. And I bet they would apply the same logic to someone on death row or with a terminal illness.