Now before everyone jumps on my case for this pick, let me explain.
Most will want to see Jake Delhomme crucified on this superlative, but that just isn't the basis for the "award." The category is WORST MENTAL mistake. Not worst decision, worst play, worst throw, etc.
In the game in Dallas, the Panthers were down 13-7 with under six minutes to go. The Cowboys had pretty much controlled the second half after Carolina had controlled the first half.
The Panthers started with the ball at their own 10, and after a 12-yard DeAngelo Williams run on the first play of the drive, faced a 2nd-and-10 after an incompletion.
Delhomme took the snap, took a short drop, and fired the ball on the slant route to Smith. Only problem was, Smith was nowhere to be found. He had broken the route off to the outside as Delhomme released the ball in hopes of creating a big play.
Cowboys' corner Terrence Newman came up with the interception and took it to the house, sealing the game for the Cowboys.
Smith's mental mistake was trying to force a big play when it wasn't necessary. The play call was a quick slant to Smith, and he didn't run the quick slant. Plain and simple. The Panthers had scored their only touchdown of the game in the two minute drill and had more than enough time to go down the field and take the lead with a score. A win in Dallas would have this team looking at themselves in a much different light after the first quarter.