I'm in no way affiliated to this guy, but I thought I'd share my 2 satoshis.

When Netflix detects unusual activity on an account, it forces a password reset (and you get a password error). It doesn't necessarily mean that the seller changed the password. In fact if that's the case, all it takes is a password reset using the email.

However, there is a common pattern of sellers disappearing when a ban wave happens or when accounts lock, so take 'warranty' from anyone with a grain of salt, unless you see feedback about that specifically.