In spite of being being hurt, zaroff congratulates rainsford on his "malay catcher", why?

In “The Most Dangerous Game,” by Richard Connell,
Rainsford, a skilled hunter, finds himself hunted as prey by the deranged General
Zaroff.  Rainsford falls from a yacht and miraculously survives a swim to shore. He
initially feels welcomed and relaxed upon finding a mansion in the middle of an island.
However, he quickly learns that the mansion’s inhabitant, General Zaroff, has made a
sport of hunting humans. Rainsford becomes Zaroff’s hunted
prey.

Zaroff promises Rainsford his freedom if he is not
captured or killed by the midnight on the third day of hunting. Rainsford reluctantly
agrees and puts his wits to work in an effort to remain alive and elude capture. He
builds the Malay mancatcher so that Zaroff will be injured if he pursues him. The plan
works and Zaroff is wounded in the shoulder. He congratulates Rainsford because he
realizes that he is a skilled hunter. For Zaroff, the thrill of hunting humans is their
ability to think and to plan. Rainsford is proving to be the most skilled and
calculating hunter that Zaroff has ever sought. He is enjoying the hunt. Rainsford’s
hunting experiences in Malacca and other places around the world, have given him great
knowledge in capturing prey. He uses that knowledge to wound Zaroff, who is thoroughly
impressed with his skill.