VAC does detect cheats if they are run with .exe or the developers can get their hands on the cheat to see how it runs and then detect it. ESEA very intrusive AC detected this private hack, and banned smn. Then ESEA admins contacted Valve and helped VAC developers update VAC accordingly. VAC will not catch another single private hack this way, unless someone leaks them more information. Flusha is obviously using another private cheat and isn't dumb enough to use it with ESEA anticheat, so he will never be caught by VAC.
Every clip from flusha could be just luck, except for the cache clip. That is as blatant as it gets. Crosshair glues on top of enemy, through a wall, he sprays without even moving his crosshair, landing EIGHT (8) (yes, seriously, EIGHT FUCKING BULLETS), to a long range targer. EIGHT BULLETS HITTING THROUGH A WALL WITH STATIC CROSSHAIR.