This case didn’t happen in a lonely, dark parking lot at night. These were two idiots in a shopping mall. They should’ve been arrested and charged for harassing people. I don’t feel sorry for the prankster. But, I’ve had far more threatening encounters with strange people, so I think the delivery man overreacted. Apparently, the rest of you disagree with me, so we’ll have to leave it at that.
And it didn't involve an amorous pursuit, nor an annoying salesman -scenarios you introduced (and where the intent of the perp was a given).
In any of the cases, it is the perspective of the victim (who does not have psychic abilities) that is important. Just because a situation doesn't frighten you, doesn't mean the same for others.
When someone tells you to stay away, you stay away. If someone is disturbed enough by another's behavior to be so warned yet they continue to close in, they risk the fight/flight response which may get them killed.