I am putting my money on the author clicking through the popup on OS X after you login to Gmail.com offering to keep the credentials and use them within the OS. I'll try to find a copy of this screen. IIRC it is clearly different from just Safari saving passwords but it's highly likely that people will click through it.
Edit: here is the screen I am referring to: http://photos2.appleinsidercdn.com/MLSafari2.030512.png