If I'm not mistaken, Nevada is a hybrid. That is, you may stand your ground in your home or vehicle, but you still must apply the reasonable person standard. What I mean by that is you may use deadly force if a reasonable person would believe their life was in danger or they face serious bodily injury.
Every situation is different. For example, you can be in your home, a person can walk in through an unlocked door and begin taking your property. If that person did not show any intent to do bodily harm, lethal force would not be justifiable. This is different than the oft' talked about "castle doctrine" where lethal force is applicable regardless of the threat level posed by an intruder in your home.
Now, if you are on the street, and a thug pulled a gun on you, you can argue that running posed more of a danger than standing your ground. You can't run faster than a bullet.