i feel like lee hyori most likely know some insider stuff prob from staff or some ppl within the industry that work with them etc. to know that it was not a case of bullying but conflicts within the group.. i mean after all the industry is relatively small..and like from some of the comments she herself know what is like working in a group with others and while often we see members in a group all getting along well sometimes its not the case and that happens just like in any workplace really