Dark Souls 2 does not in fact use VAC at all, it was intended to yes, but it doesnt because FROM stated that they were trying to make sure that VAC would not false-flag accounts who use graphical upgrade mods, the kind of mods that made Dark Souls 1 a massive success on the PC. However most Forums, Steam and otherwise, have a no naming&shaming policy, which results from the fact that often times the alleged cheater is not actually cheating at all.
Take for example a false-positive VAC-ban. They will not admit that their system fucked up, they wont "unban" you even if you were banned for no fault on your own by using some normal mod. You are now branded for life, even IF you actually cheated, even just once, this stigma will stay with your account because it will not be removed by Valve after a set period of time, which to be honest it should. If VAC does not detect you "cheating" again for X number of months or years, the ban should be removed until such a time that you cheat again, kinda like how the Escapist Warnings work, eventually your record is set back to zero if you do not keep adding more warnings.
That being said, if you can go around to a forum and publicly shame people for cheating, whether they are or not, it assigns the same stigma. And often times its really a case of people being sore losers. You got beaten in a fight? Well clearly the other guy had to be hacking, no one is better than you. Thats the problem and thats why public naming and shaming is forbidden.
However to get to your story, im uncertain if there IS a infinite-stamina hack, Alonne Greatbow does not use the entire Stamina-bar, can be fired rapidly (compared to the Dragonslayer Greatbow) and with a Chloranty Ring (the +2 is preferred) you can essentially keep firing endlessly since the windup time for shooting is long enough that the difference between having stamina and having none is very slim, you can actually fire it with just 1% stamina which may have been regenerated while the arrow was still traveling to its destination. I know this because one of my builds actually uses it as a ranged-option in PvE, coupled with the knockback you can essentially pin enemies down without fear of them actually getting close. As for the "not falling off", yes thats the parry-airwalk glitch which is going to be fixed in the next patch, as well as binoboosting (exploiting that lets you move at higher speed than sprinting without stamina-drain). Although i cant be sure, i've only seen the latter in action once.