If you look at Painter's body of work from last night's game, he was atrocious overall.
On his first drive, he missed a wide open Pierre Garcon who would have easily scored a touchdown had Painter not overthrown him. It's a throw that all NFL quarterbacks have to be able to make. He didn't have to thread the needle, he just had to be able to get the ball to him. He failed.
On his next drive, the Colts handed the ball off to Joseph Addai for three consecutive plays and gained 16 yards total. Then Painter threw the ball. And the Colts gained zero yards. Painter failed to complete both of his throws, ending that drive.
The next Colts drive was classic Painter. He dropped back, failed to sense the pressure, and got hit by James Harrison. In classic Painter fashion, he failed to hold onto the ball when he got sacked, and Troy Polamalu returned the fumble for a touchdown. The Colts now trailed the Steelers by that touchdown.
Painter finally stepped up on his next drive. He led the Colts 80 yards to tie the game. He was 5-7 for 60 yards on the drive, and did hit one deep pass to Garcon for 27 yards. He also completed the hand off to Addai with Polamalu already in the backfield on the play where Addai punched the ball into the end zone. For maybe the first time in his career, he looked like an NFL quarterback.
Then, on the final play of the game, Painter short hopped his throw to Austin Collie. Collie probably wouldn't have scored on the play, but it's the fact that he failed to hit him. Again, Collie was open. He just had to get the ball to him. He failed to do that.
Painter is just too inconsistent. The Colts don't know what they're going to get with him. Will he misfire on multiple throws? Or will he lead his team down the field to tie the game? Inconsistency is one of the worst qualities a quarterback can have. Especially a quarterback trying to play in Peyton Manning's offense.
If the Colts must rely on Painter for their remaining 13 games, it will be a failed season for the Colts.