It may have been purposeful, but it really begs the question to whom he did what, or how this would happen to him, like the reason.
That aside, who knows what went down in his personal life. It's just extremely uncanny how suddenly he just died, especially so after he was about to start cashing in his money for his lifelong career. He was a superstar of Basketball, some compare him to Jordan.
Then again, someone from his family or whatever who wanted to rob his assets, wouldn't really be able to rig a helicopter. This is why there is some credibility to the aspect that this was freak accident.