The recording shows that although your stored site indeed has a stored password, which is protected by the master password, you are actually authenticating with a public key:

Authenticating with public key "kane\dennis.fair@NOC"

So the password is not used/needed for the authentication at all.

When I set up a site, I set a master password on it and at one point when needing to go to a different area after accidentally starting that site session, it asked for the master password. I clicked cancel, thinking it was going to close the initiated session, but instead, it just started the session anyways.

I did this a couple more times, through the site session file as well as from the main console and both resulted the same bypass.

WinSCP v6.1.1