Consider a man who is able to speak with his now deceased father using a radio that is sending his signal back thirty years into the past (anybody get the reference?). He is aware of how his father died, so the man warns him not to go with his gut when he’s in a fire. The man tells him to go the opposite direction (because he heard from family friends that he would have been okay had he gone this way). The man’s father listens, and he survives. He’s okay.
As a result, someone else survives the fire as well- a murderer. He kills the man’s mother, and will go on to kill several other women. The father and son work together to stop the killer, but that’s irrelevant to the topic at hand.
This man now has two sets of knowledge, since he changed the events: what “really” happened (his mother died instead of his father), and what “could have” happened- his father dying and his mother surviving.
Now consider that another man offers the man we’ve been talking about two choices. He can go back to the time before he found this radio and stop the alternate timeline from occurring, or he can live with the consequences of his actions.
This puts the man in a very tough spot. Does he choose to stick with what he caused, thus allowing his father to survive the fire? or does he decide to go with the timeline that spared his mother and several other women?
Now for the even bigger question: let’s assume that this man chooses to save his mother. He chooses not to use the radio, allowing his father to die in the fire. Is his allowance of this the same as the man killing his father himself?