It's possible, likely even, that Goff performed better last night than he had in general in practice.
My reading of the situation is that there is too much sensitivity here to critiques of Goff and that in reality the reports on average have been more middle of the road than negative or positive to one side.
We saw the same thing last year too, when people looked for reasons to bash the negative camp reports on him. I recall vividly some accusing Fisher of having an ulterior motive for not starting Goff earlier than he did. Goff didn't look THAT bad in preseason and Keenum, of course, wasn't very good. And when Goff looked decent over his first two real starts that conspiracy theory accelerated. But we eventually came to understand exactly why Fisher didn't think he was ready to start earlier.
Vinny B is just a guy in the Rams pocket. As long as things are going as the Rams hope, he'll look like the one who knew better.