When I run the example.js on my Windows 8 machine I can see my password even though silent is set to true. Haven't tested this on other Windows versions though.
I thought that programs had to manually echo input in Windows (in my experience of DOS to Windows XP, I never came across any UNIX-like ECHO flag)... Maybe see if there is code in this module that manually echoes input in Windows, and see if it checks the silent flag.
I'm experiencing the same issue on Windows 8...
also seeing this on Windows 10 with GitBash