In this work we provide a model-based analysis of the moving block control and quantify the rate of spurious emergency brakes (EBs). We consider as a reference a typical implementation for metro by Alstom Transport. We derive the general formula for the EB rate, that requires to provide the loss and delay model. The delay model considers processing delays, computation times and communication delays. For the loss model we start with the case when packet losses are independent and homogeneous. By developing the general formula we derive an exact expression for the EB rate. We proceed then with a more elaborate loss model, when losses are no longer independent.As it becomes hard to derive a closed-form expression for the EB rate, we evaluate it using efficient Monte Carlo simulations. The theoretical results are validated via discrete-event simulations, including simulations with ns-3 for which we have developed additional modules for train systems.