I wouldn't say "he kept us within a TD". More like 'we were within a TD despite zero production from the QB spot'. I mean heck, we had less that 115 total passing yards.
Outside of the very first drive of that game, he was so uninspiring and missing throws constantly. I am not particularly for Roberson this year, he too was very uninspiring at times. But, I can't deny that we were able to see him improve and get more comfortable the second half of that year. Which to me gives more hope that the hypothetical of maybe Fagnano also would have improved over time. I think ideal world for me is give Roberson the keys Week 1, with the idea that McDonald or Welliver takes over if we start the season 2-3 or worse.