I was just watching the old Predator 2 movie , and I have this quetion bugging me...?

At the end of the movie, when Danny Glover finally killed the Alien inside its own spaceship, and then the other predators appeared . At first I thought they came to retaliate, but instead they didn't touch a hair on Danny's head, but calmly took their departed friend away. In the movie's point of view, I didn't get it why the other predators left Danny unharmed, if they should return to Earth again? remember after the spaceship left, and Danny was walking away from the explosion, he told the other cop he''ll get another chance? I'm totally lost... someone explain please!!