Not possible as it uses a thermo-pile.Thermocouple makes about 50 millivolts where a thermopile makes 750 millivolts. Easily measured before one replaces it. Connected to the gas valve you should see above 400 under load.
High limit is probable, but not the only possibility. Use you DVOM to troubleshoot before replacing parts. Electrical contacts, gas supply, and pilot flame all have a effect on this.
Some high limits have to be reset. Like these
So if it tripped, was it in a high setting or was the thermostat off. A good tech would take the time to measure the calibration and test the thermostat.