6.) The Memphis Grizzlies and the Boston Celtics signed a player approved by the NBA whom according to the NBA had a career ending injury - FACT!
The adjudication by the NBA's doctors that Miles' injury was career ending was only speculative, and a prediction. It could never be anything else, such is the nature of the beast when you're trying to predict the future. The NBA put the 10 game ruling thing into place as a safeguard in case such a prediction ever turned out to be wrong, and, in this case, it was.
11.) You are making an assumption that appearing in 10 NBA games constitutes a player being healthy enough to have an NBA career. There is no medical explanation for this being true. Anyone at any age with any level of health can stand on a court for 10 games.
Conversely, why was it any less healthy for Darius to return on his surgically repaired knee than it was for, say, Dikembe Mutombo to play these last three years? Of course, Darius risked popping his knee again every time he jumped, and causing perhaps lifelong damage to his knee. But for all we know, Mutombo could have been taking 3 years of walking pain-free from the back end of his life for each year that he backed up Yao Ming on the Rockets. He, too, risked a career ending injury every time he took the court and left the ground, because he too had decidedly haggard knees from several centuries of playing in the NBA. Medical teams may well have been able to say without fear of contradiction that, while Dikembe
could play, he
shouldn't. And remember that, of the two, it was Dikembe who suffered a career ender, not Darius.
More to the point - Darius didn't stand on the court for fleeting moments in 10 games. He was in a rotation for 34 games. The proof of his ability to not only take an NBA court, but to perform acceptably well on it, came from the fact that he did it. Sure, a yardstick as arbitrary as the 10 games one COULD, in theory, be manipulated by suiting up a pensioner and stapling them to the half court line for 5 seconds at the end of the first half for three weeks. But this didn't happen. Whatever Memphis' motives, Darius' health was acceptable.