Conflict in a team affects its people. People have personal perspectives. Subjective, not objective. Both real and a factor. Opinion counts, for it is among the fundamental drivers of behavior.
Americans value as evidence both facts and personal opinion. See an American curriculum vitae (resumé). It always either cites or offers references. See the sales/marketing efforts of any American company. They always either cite or offer a customer list. See the American judicial system. It always allows for supporting witness testimony.