Running a toss pitch was the right call? Let alone Bettis fumbling, you let your QB flip the ball to the RB? No way, terrible call, choke call.
worse case scenario if you kneel down three times and make them waste the TOs, then try to score a TD on fourth down and don't make it -> the Dolts get the ball on their 1 yard line with no TOs and maybe 45-50 secs on the clock. Then at least you haven't fumbled or given them any other signs of hope and you put your D - which was terrorizing Manning - the real strength of your team on the field to stop the Dolts. Any which way you do it, you had to make them burn at least two TOs and get to 3rd down, minimum, before you try to run a play. Cowher lost his head, plain and simple.