I don't see a problem with taking kills when you and another are fighting over the area but when you go out of your way to harass him and follow him around and ruining any fun he had in the game. Especially in the Tunnels, you can easily keep to yourself in there with such a short spawn time for the bats, you could just sit in a little group of 3-4 squares and run back and forth.
Find content
Not Telling
