Artie
On the neo-classic 737 (heck, all the pre-FADEC Boeings), it is true that the throttle will auto-retard for uncommanded T/R deployment.
On FADEC, it's all done with electrons, the throttles won't move for uncommanded deployment. However an uncommanded stow can still move the throttle.
That being said, post Lauda, all Boeing airplanes have triple redundant systems to prevent uncommanded deployment. The likelihood of all three systems failing is way less than 1/billion hours (full up it's more like 1/trillion hours). Bum indication is orders of magnitude more likely.