There is a difference from trying to prevent a confrontation/assault/death by violence and telling someone to attempt to save someone who is dying.
There is not!
You are not legally obligated to do as a 9/11 operator says.
Police are not even legally obligated to protect you. You can call 9/11 & they or the police could go take a nap while you are raped & you can't sue them.
Is too!