What's to get confused about? Two different things. First was about what someone hears, second was a statement about perceived thought of where string vibration ends. If you place your hand/finger across the strings beyond the nut/bridge, you may or may not feel the vibrations when the strings are strummed. The purpose of the nut and bridge is to affect the vibrations between them to be in scale. They do not stop the vibrations entirely. You can see this vid where the player plucks the string(around the 1:15 mark) behind the bridge and uses the trem. That couldn't happen if the strings were "dead" at that point.