We perform a comparison between an innovation and a residual based integrity monitoring in Extended Kalman Filters for the GNSS/INS hybridization. In this paper, we restrict the study to the detection of abrupt snapshot faults in order to get an intuitive insight. We study the differences in the distribution of the test statistics and the computation of the thresholds. We derive and compare the minimum detectable bias and we provide expressions for the protection levels for both approaches in the single fault situation. We compare them with the classical residual based GNSS RAIM algorithm. Additionally, we perform a sensitivity analysis of the integrity relevant parameters to the inertial sensor quality.