This guy should have known that people would kill a lion and other big cats to save the life of a suicidal man. People view human life as being above the innocent cat or even ape when it comes to a perceived threat to a human life. It is sad to see the Lions be put down because of that actions of a thoughtless person.
He must have been on drugs or wanted to suffer a horrifying death because there are a whole bunch of other ways you can end your life other than going naked into a lions' den.