Schneider-X
[11] Champion
You should probably update that CE moves can be JG, and that only the initial hit of a CE cannot be GI'd.
Something to keep in mind is that clean hits do stale in SCV. The more you use a clean hit move in a match, the less chance you have of getting a clean hit (I don't think LB+RB training reset resets this also, as it only resets the position of the characters and kind of counts as a "new round"; staling carries over rounds). The best way to test this would be to do the move once, quit, restart the match, do it again, etc. And get a larger sample size too, something along the lines of 1000. Don't worry, it'll only take a few dozen hours. Get to it, champ.
How did you find this out? Just an observation?