You can still notice difference between the authentic retail pair and the UA ! but you have to know them because of the nike/jordan inconsistences.
Just a quick tip for exemple:
View media item 2425282
This inside panel shape is smooth (like every other retall XII's) and i didn't seen fakes with a correct shape at this time. They are "bulky" like the red lining.
Other thing, i don't know if every pair are like this but both black and white pair (for me) have a kind of triple stitching in this area:
View media item 2425290