Michele Roberts is a smart person. You don’t go from being a public defender to major law form partner to becoming the first female head of a major professional sports union without having a healthy combination of savvy, smarts and substance. So what was she doing last week when she told ESPN that the NBA’s collective bargaining agreement, with its maximum salaries, age limit and rookie salary scale, is “un-American?” (And by the way, that “un-American” comment clearly struck a nerve with