If it was from the TV, you'd more likely see something in history like, 'Text not available, click to play recording'. That will give you a very short audio clip of what woke your device up. It might also say 'Voice request not intended for your Echo—nothing was returned', but if yours was responding, then something was returned. Anyway, maybe check that out. I have a cough at the moment and my Echo wakes up regularly, sometimes telling me it doesn't understand. No help there then!