Just bad luck? It was entirely preventable because (a) it was only a friendly game and (b) in RLC's case, he should not have played at all given his fitness and back issues. He wasn't exactly a 100% healthy, fully fit player etc like the others.
Even though it was for a good cause, the club got criticized because they arranged a friendly ahead of a cup final. They risked players getting injured and unfortunately, one happened.
Are you seriously comparing the two situations? USA or not, going to watch an NBA game without having to exert oneself physically (e.g. playing the game) is completely different to actually playing a game!