I wonder what happens if you're holding your Windows 10 device, but you're still in hearing range of your Echo? If you say "Cortana, open Alexa", does the wakeword Alexa also cause the Echo to start listening, so that you end up with both devices attempting to service your voice request, and vice versa? Or do both Windows 10 and Echo devices have a sort of anti-wakeword when they hear the name of their counterpart agent?