A fault-detection method, system, and device for a cryosurgical system that avoids a false-positive detection of a fault condition, such as fluid ingress within the system. The fault-detection mechanism may generally include a driver having an active mode and an inactive mode, the driver generating an output signal when the driver is in active mode, a detector, the detector capable of receiving the driver output signal, and a detector verification controller in communication with the driver and the detector, the detector verification controller changing the driver from the active mode to the inactive mode when the detector receives the driver output signal. The controller may determine a true fault condition if the controller determines there is a correlation between the signal received by the detector and the driver output signal. All other possible fault conditions may be ignored if the controller determines that the signals are not correlated.