I have found some recent questions that have by-passed the quality filter and doesn't show any revision. My guess is that the OP found a way to by-pass the quality filter in order to get their question posted then edited the question.
I'm wondering if there is some sort of automatic question quality enforcement for edits made by the OP that might be failing or should be improved.
- What should we do about users adding nonsense to question just to meet quality standards? (discussion from 2011)
- Add recursive defenses to the quality standards (feature request without status tag from 2011)
- Add attempts to game the "quality standards" filter to the Low Quality queue for review (feature request without status tag from 2013)