That family left the island several years ago; the one brother or cousin with a resort named after him is still around, but he was never the problem. They sold their resorts and left at lest 4 years ago. While the particular individual is probably gone too (can't remember his name), he might be living in the hills still in an isolated life of repentence. Pretty sure he is out of the picture though... either way, his protection is gone.
Koh Tao has its issues, but the wild west cowboy days are gone. Much of what happens is specifically because of its isolation... but there is a lot of drug and alcohol abuse, especially among long-time residents. Having someone die in their sleep happens... and things that if you could just call an ambulance you would be fine can easily lead to death there. Still one of my favorite places on earth.