We're not given this guys name, so it's our first John Doe in the Manly Men of Mankind. Mr. Doe will be inducted into the MMM not because he killed a mountain lion. He used a gun, and usually that means he's excluded from the MMM. But he did it to save a puppy that was being attacked by said mountain lion.
Now if you're killing to save man's best friend you get in the MMM by the Michael Vick Offsetting Action Clause.
So John Doe, welcome to the Manly Men of Mankind.
Man up, America!