If you knew anything about academia, or if you even bothered to carefully read my post instead of nitpicking, you would understand that just because something is in general true, doesn't mean that there won't be hundreds of papers showing how this thing fails to be true in special cases, or to a very small extent.

Regarding martingales, a martingale is defined relative to an information set (you know what a martingale is so you already knew that, right?). Saying that there is no reversion to the mean implies being a martingale with respect to the weakest possible information set (the history of prices). Traders, whether high frequency or others, may have extra information outside this information set.

In short, stop nitpicking and revise your understanding of what a martingale is.