You're contradicting yourself. You said "he did not play a perfect game," which is the same thing I said. But then you say he gets an A+ because he got no help from the run game. So you're grading on a curve in that sense, but not considering the low quality of the defense he was playing. Bottom line, an A+ grade is reserved for a perfect game, and you said yourself he didn't have one.
By the way, a dropped pass doesn't always necessarily relieve the QB of any liability for the failed play. Sometimes he shouldn't have made that particular throw in the first place. Trask's overall decision-making and execution against the Vols was just a little bit short of his usual standards of excellence, that's all. I'd chalk it up to being a little uninspired. Tennessee really sucks.