I got to say - from that clip he seems like a really cool guy. Modest. Well spoken. And I had forgotten what an amazing physique he had at his peak.
I wonder if he still has the house? Looked nice to me. If he had paid that off and still lived there he would still be living pretty sweet I imagine.
About his kidney problems he got later, you've got to feel for the guy. For any bodybuilder, something like this, whether a shoulder injury, a back injury, or an organ injury - it really sux. Because no matter how hard you are willing to train, its not something you can fix through hard training. And also, because at the time, they don't usually know its going to happen. And your whole identity as a bodybuilder changes, not to mention your physique, your career, and how people perceive you.
I hope Flex proceeds happily into the next phase of his life and does as well in the next 20 as he has done so far in his life.