You are still thinking as though someone can 'choose' to go back in time and kill themselves. Choice has no bearing on it. Either something happened, or it didn

You are still thinking as though someone can 'choose' to go back in time and kill themselves. Choice has no bearing on it. Either something happened, or it didn't. It is still consistent that a cause is needed for an effect, so an effect cannot eliminate a cause. You're just describing something that can't/doesn't happen. There are plenty of rules that describe things that can't or don't happen in space. You wouldn't have any concerns with me saying it's impossible for me to go to the bathroom in my own house and when I walk out, I am in your house. How does the bathroom door magically know which house I am in?