That is what Kyle Shanahan told Mark Schlereth. The college game is so different than the pros that it's very hard to evaluate college QBs for their ability to transition to the pro-game.
About all scouts have to go on is "he has elite arm talent" meaning he can make accurate throws. But, can he read NFL defenses in under 2 seconds? Can he learn to throw open receivers rather than waiting for the WR to get open, then throwing the ball, which they haven't time to do in the NFL.