I have had an Echo for over two years, and also plenty of Dots around today.
I recently have noticed a marked increase in "number of false or unintended responses from Alexa" ever since the new Dots were released and the firmware was tweaked, and it's My voice that triggers it. My devices are far enough from TV, as they should be, to be affected. Just this week I was lying in bed, and gently cleared my throat so as not to wake the wife, and the Dot across the room blurted out: "I'm sorry but I did not quite get that." (did not wake wife, tho.)
I really believe Amazon has cranked up the sensitivity for listening. I doubt this portends any litigation issues, tho.