I agree on your assessment of why he catches flak: HawkeyeGamefilm used a hockey analogy and called his miss of a wide-open Smith last week an "open-net miss." It is like the opposing team has pulled its goalie, the easy play is right in front of him, and he misses it. That is hard to get out of your mind, even if he makes a bunch of great plays to counter that miss.
But I don't think it is a matter of being overcome by the moment, or making those plays against bad opponents and missing them against good opponents. He misses those plays against good and bad, the effects are just amplified vs. the good opponents.
I really don't think Stanley is ever overcome by the moment. If he was, he wouldn't have led the comeback against ISU in his 2nd start, he wouldn't have led the route of OSU in 2017, he wouldn't have led us to the doorstep of a comeback against a stellar PSU defense by marching down the field like a knife through butter after our offense had sucked for the whole game. The moment doesn't get him, his own brain does. He sees wide open TD, and he doesn't think, "Don't throw the INT," he thinks, "Oh Dear God, don't blow this, he is WFO!" And as soon as you think don't blow this, you become mechanical and you mess up. He becomes
Chuck Knoblauch trying to throw to first base, or
Rick Ankiel trying to get the ball across the plate.
We saw this with his overthrow of Hock vs. PSU, his underthrow of Ragaini vs. Miami-OH, and his overthrow of Smith vs. Rutgers, and who-knows-how-many misses to Fant last year. He tries to be too perfect, and that is the issue.
What I like so far this season is that those moments seem less frequent, and when they do happen, he shakes them off and gets back to work. His open-net miss to Smith was followed by a well-thrown screen to IKM, and then a beautifully thrown crossing pattern to a wide-open Tracey for the TD.