Walter, the second-year quarterback for the Raiders, was removed with just over 10 minutes to play Sunday in a 34-20 loss to the 49ers after throwing two interceptions and a lateral that was returned for a touchdown in successive possessions.
Walter was coming off his best half of football when the Oakland offense disintegrated. In the first half, Walter was 10-for-15 for 138 yards and a touchdown. He was 4-for-8 for 26 yards and the three turnovers in the second half, during which time a 13-7 lead ballooned to a 31-13 deficit.
"I wanted to stop the bleeding for him because he had made three mistakes that were crucial and I didn't want to compound it on top of that," Shell said. "So let's put Tui in the game and see what happens. It's not to take away from Andrew. His growth has to continue."
Shell's dilemma was to determine which scenario is worse for a young quarterback -- hurting his psyche by pulling him from the game, or destroying his confidence by leaving him in for what promised to be even more turnovers.
"He was pushing, trying to do too much," Shell said. "On the lateral play, we told him that was not a good throw. There were other options for him."
If Walter was upset at getting the hook, he hid it well.
"It's a coach's decision. I'm not going to worry about that," Walter said. "Was I surprised? I didn't play great. If you don't play great, you can't expect to be out there all the time, I guess."
The 49ers certainly know they have a lot of room for improvement. Their 34-20 victory over the Raiders, was a step in the right direction because they defeated a team they should have handled.
"A win gives us a lot more hope for where we're heading," 49ers coach Mike Nolan said. "A win builds confidence. It's hard to say where we are, because I know who we played. But a win is a win."
The 49ers (2-3) made plenty of mistakes in their victory over the Raiders, but the Raiders outdid the 49ers in that area. The 49ers blocked a punt, came up with four interceptions and returned a backward pass for a touchdown.
A cynic could look at everything good the 49ers accomplished against the Raiders and determine those plays happened because of Raiders mistakes and not because of anything the 49ers did.
Raiders quarterbacks Andrew Walter and Marques Tuiasosopo made several ill-advised throws or passes that were badly off target that resulted interceptions. When Walter's backward pass fell to the ground, the Raiders did not try to recover the ball. Niners rookie defensive end Melvin Oliver grabbed the ball and trotted 12 yards into the end zone for a touchdown.
"I have a different opinion," Nolan said of the 49ers not earning the turnovers. "In the past we've had a lot of those balls fall short and nobody was there to get them. Being in the right place is really important.
"It's like a win. There's no ugly win in the NFL. When you win, that's a good thing. I don't care if you're undefeated or not. The same thing with a turnover, you can look at it a lot of different ways. None of the teams that intercepted Alex last year (apologized)."