i was wondering this myself since i have him...i believe he was taking out because he had an unsportsmanlike penalty and cost the niners 15 yards. he wasn't doing very well at the moment so the niners benched him in favor of hicks who took the niners down the field.
The Contra Costa Times reports that Kevan Barlow was benched in favor of Maurice Hicksafter when he threw the ball at a defender after being hit. "I was down and (a Panthers defender) jumped on me," he said. The team received a penalty for his actions. He also fumbled twice -- officials considered him down before the ball came out. "What Kevan did, you can't do that in that situation," said head coach Dennis Erickson.
Hicks really only had one good run. The rest of them were almost all in the 0-2 yard category. On the upside for barlow owners, hicks Missed 2 key blocks at the end of the game that led to big plays for the carolina D, so I doubt barlow will lose his job.