This question already has an answer here:
While review posts in the "low-quality" queue in the new review system, I encountered a short post consisting of a link along with a somewhat terse explanation. Here is the question, but the post has been hidden by the review system.
It was long enough to convince me it didn't belong under "link-only non-spam", and I deemed it looked good. Upon clicking "Looks good" I met the "This post has severe quality issues" warning instructing me it had severe problems and has already been dealt with.
The only problem was the post didn't have any obvious problems (barring my developing sense of acceptable posts.) Certainly it was not off-topic or offensive.
Please, before you mark this question as a duplicate, here's what I want to know: in the situation an "obviously good" post gets this warning, how would I mark it as such? Putting my specific example aside, it seems there should be some means to disagree, or at least see the reason it was put up (I suppose my example might have been especially well-crafted and genuinely useful vendor spam.)