He clearly defines what he thinks Cahoon is doing wrong.
Brady holds him totally accountable for what he's doing, he tells him how important it is that he does his job and what he's costing his team by doing it wrong.
He acknowledges Cahoons effort, but doesn't ever give him a pass or sympathy and demands he does it better.
That was some beautiful coaching.
Hopefully Cahoon responds to it and makes the necessary changes.