MIAMI — Caron Butler does not downplay the moment, even with the assignment limited to summer league. The goal for the former Miami Heat forward and current assistant to Erik Spoelstra is to one day take the next step, as an NBA head coach. But no, Butler said this past week, guiding the Heat at the Sacramento and Las Vegas summer leagues, starting Monday, is not his first go-round as a head coach. The previous time, in fact the only previous time he worked as a head coach, it was far more personal.