Utilization Review and RNs

For the past 5 months while out for injury(on the job) my light duty work was to do utilization review, case management, chart audit, and such. The position was open and about a month after I was doing it, my employer posted it to find a permanent replacement. I applied and was told I would need to be an RN. My supervisor then informed HR she would be happy for me to work under her license while I finished up RN school (Im an LVN now). I was told I was being seriously considered for the position but did not get it. I had the pleasure of training my replacement today after five months on the job. She does not hold any nursing degree nor will be attending school for it anytime soon. She is a social worker. I have had a lot of difficulty helping her understand the relationships of medical necessity. I live in Texas and I thought you had to be an RN for the job or at least have a nursing degree......does anyone know different? I don't mind not getting the position, but don't understand the reasoning. Any information anyone has on this would be helpful. I guess my biggest concern is for possible fraud of medicare and abuse of the system. With decisions like this how can we expect people to recieve the best care possible?