Not at first look. But Indy only had 11 first downs and held the ball for less than 22 minutes. That is at least partially because of QB play. Especially when he's 9/17 for 67 yards, no TD's and an interception.
I agree with you, the Colts are built around Manning. Without him, they are unable to put points on the board or even go 50/50 on TOP.
That being said, it's inexcusable that the Colts have stuck with such a blatantly bad backup QB as Curtis Painter for the last 2 or 3 years. If someone is going to get canned, they should get canned for making the decision to keep Painter, not for the Colts playing the way they are with Painter.