What were the 76ers doing in the final three minutes of the Game against the Nets?

The last three minutes of the 76ers against the Nets are simply tactical no tactics, to score no goals, the head coach is stupid, as if not even a timeout will not be called, at most the 76ers lead by 10 points, and finally overtaken, the last ten seconds of the bottom line ball penalty error, I now feel more and more that Rivers is the most overrated head coach in the NBA, twice 1:3 lead was reversed is not without reason.