Aqib Talib wasn't the Aqib Talib we saw in the beginning of the season. Hobbled by a hip injury and the trash talk of Steve Smith, Talib was off his game both physically and mentally.
After being beat by Smith (though it was more a good play design as Ginn (I think) essentially set a pick for Smith and Talib got lost in the shuffle. As Jon Gruden points out in the video, Smith and Talib have had their battles dating back to Aqib's time in the NFC South as a Tampa Bay Buccaneer. Still, no excuse for Talib to let Smith get in his head and start a fight like that. He was later beat for a 40 plus yard bomb to Smith.