The way your helicopter is set definitively helps, but if you are using collective pitch helicopter, sooner or later it won't stay true during pirouettes. So, what you have seen are piloting skills - and people did those pirouettes to show off their skills - not their helicopter setup.
To be able to constantly pirouette cp helicopter for the duration of the battery one needs to know how to constantly correct it - no matter where the helicopter's nose points. Because of that feature, slow pirouettes (as in at least 5-6 seconds a revolution) are perfect orientation and general rc helicopter control practice. Many here that claim that they are really good would struggle doing slow, very controlled, continuous pirouettes - in both direction! (me included).
So, if you master how to control helicopter while it is slowly pirouetting you will be able to correct it at any orientation. That, usually, leads to less crashes due to brain freezes. If you are to progress with general rc heli skills it is really good idea to start practicing them. Now.