Bad clock management is the least of his troubles. His teams are consistently outplayed in the second half of games, which means the opposing coach is always out-performing him when it comes to making adjustments.
Also, his teams demonstrate some of the worst football fundamentals (missed blocks, poor tackling, mental mistakes, etc.) I've ever seen. Even when the Giants were up 38-14 I was rattling off a list of players and individual plays in that game that even a marginal high school coach would never tolerate.
Bad clock management is a symptom of his game day inadequacies...and it cost us the Arizona game. He's just no good on the sidelines. Period.