A question for a lawyer regarding Human Resources.?

My fiancee works at a senior care home facility in Palo Alto, CA and during a graveyard/nocturnal shift she and an irresponsible co-worker were on duty. In the middle of helping a resident who had fallen, a page came in from another resident who had just returned from the hospital. My fiancee who did not trust to leave the resident with her co worker, finished up as quickly as she could and then proceeded to help the paging resident (elapsed time, 4 minutes). The resident complained that no one helped her and called her son to complain, triggering the move of this resident out of this facility on the demands of her family. Today my fiancee gets a phone call from the scheduling coordinator and the executive director of the facility, blaming her for the mishap and demanding to know how she handled it. She answered honestly, stating she contacted the resident's son and explained to him the reason that they were not able to respond to patient that exact second and then spoke to the scheduler, explaining with the lack of staffing over night, and being placed with a coworker who does nothing independently, there is difficulty in being able to be at numerous places at one time. After that, the scheduler told her that she is writing up my fiancee, and blamed the whole situation on her. Sorry for the long story, but here is my question. From what I understand, all human resource departments are neutral players in any business, and I suggested that she file a complaint against management for discrimination, and against the coworker for not being responsible and trustworthy enough to even work in such a facility in the first place. The reason I am asking for an answer for a lawyer is that I want to know if she has grounds to file a complaint for discrimination and is H.R. truly a safe place to file a complaint or should we go to a 3rd party to look into the matter?