1. A system for mitigating an overspeeding condition of a turbine engine, the system comprising: a sensor for measuring a measured speed of a gas generator turbine of the turbine engine; a processor operable to determine a difference between the measured speed of the gas generator turbine and a predicted gas generator turbine speed, the predicted gas generator turbine speed is based in part upon a commanded fuel flow to the turbine engine, so as to thereby detect the overspeeding condition when the difference between the measured speed of the gas generator turbine is higher than a predetermined threshold; a valve configured to redirect a fuel flow supplied to the turbine engine, the valve being actuatable upon a detection of the overspeeding condition; and a restrictor valve downstream of the valve and sized to limit the fuel flow supplied to the turbine engine to a predefined flow rate; wherein the resulting fuel flow supplied to the turbine engine flows completely downstream of both the valve and the restrictor valve.