I think Fortin is a lot better than he showed, and the fact that we seemingly couldn't gain a yard rushing didn't help. And I get that McClain is the future. But I don't understand why you pull Fortin so early, after spending so much time talking about how he is the guy that clearly separated himself to the be the #1. If you had said we were going into the game and two QBs would see action, no problem. Or if you said the #1 would be decided later. But to put all of that on Fortin and then yank him so early to me does a disservice to your entire team.
Clearly the coaching staff thinks a lot of McClain. If that is the case, either start him from day one and let him take his lumps, or at least say that he is going to play early and often. Don't let the entire team think Fortin is the guy, and then bench him in a state of panic after a couple of series. That isn't how you methodically build the players trust in you as a coach.