TB,
The system is designed to prevent a major overtorque but, by allowing the Nr to droop that low, you put the aircraft in a critical condition. Although EEC fuel scheduling is designed to provide 114/114% max, you should understand that when you cause such a significant demand for more power, the way the Tq sensors detect torque will result in the indications appear to "overshoot". That is simply a very momentary overshoot in the indication.
I suspect that the Tq only displayed those high values for a second or so then stabilized at a slightly lower value. Is that what you saw or were your eyeballs so large that you did not notice the details?
Regardless, did you report it and what was the determination once the CMC and the engine DCU data was downloaded?