Reassessment of the critical temperature and density of the restricted primitive model of an ionic fluid by Monte Carlo simulations performed for system sizes with linear dimension up to $L/sigma=34$ and sampling of $sim 10^9$ trial moves leads to $T^*_c=0.04917 pm 0.00002$ and $rho_c^* =0.080 pm 0.005$. Finite size scaling analysis based in the Bruce-Wilding procedure gives critical exponents in agreement with those of the 3d Ising universality class. An analysis similar to that proposed by Orkoulas et al [Phys. Rev. E 63, 051507 (2001)], not relying on an a priori knowledge of the universality class, leads to an unaccurate estimate of $T_c^*$ and to unexpected behavior of the specific heat and value of the critical exponent ratio $gamma/ u$.