He's regressed a bit every game since due to tougher competition, inexperience, and being dinged up among other things. He needs time to sit back a while and get his head and body right.
Also, there really isn't much film on Rose so there could be some advantage there. We all know how BYU has done with new QB's they've had little to no film on in the past, including OSU's Rangel this year. We don't know what all he can and can't do, especially after a week's worth of QB1 reps. What gives me hope is that Wilson initially beat him out for the #2 position in fall camp. But for all we know, the new interim OC could take a page out of OSU's playbook and turn him loose like Rangel and employ some RPO with Bernard at his side.
Cougs need to be ready for all that.