It's too early to say. There's a non-zero chance that his crazy psycho bitch ex managed to poison him. But he also loved his vices. Smoking, drinking, drugs, life was one big party for Cobes. Or at least it was until Ozzy got called home. It wouldn't surprise me if he died the day he heard the news and it took his body a few weeks to realize it.
Regardless of what killed him, his lifestyle should serve as one hell of a cautionary tale. Don't smoke, watch your alcohol intake, and do something with your life that involves leaving the house. Cobes may have brought joy to peoples' lives but it came at the expense of his own.