The empirical research allows visualizing institutional practices as a way of evidencing the absence of neutrality of the law and the problems that certain legal matters face in the daily life of the judiciary. This exploratory and descriptive research, by means of the hypothetical-deductive method in empirical research, tests the hypothesis that the justice of the state of Sao Paulo determines the expertise as sovereign, ignoring the medical background of public bodies or technical assistance opinions that differ from the expert report. With this, a non-existent hierarchy of evidence is created in the Brazilian procedural system, distancing the insured members of the social security system from their fundamental right to social security, deciding with superficial, superficial and pseudo-objective criteria. The data reveal that the hypothesis is proven, being a practice that violates not only the right to social security, but also the principle of contradiction and ample defense.