I truly think this was McDermott being in complete control. They were not "fighting" before he stopped practice and gave them a ripping. As soon as he did, all hell broke loose. It would not surprise me if he was smiling inside. This shows me that he is in complete control of this team, and can motivate them on command, at his will. Today's practice will be the indicator of his ability to "focus" the team with that fire that he produced yesterday.
command and control is the first step to team building and success