When my T said it I googled and came across the same link you've put up.

It's a little scary to think that your ex was a sociopath/psychopath because considering they are characterized as charming and manipulative, there was probably nothing you could do to 'catch early warning signs'. I hope if dating individuals with these characteristics is a habit, you will be able to keep your radar up and try to avoid the psychologically troubled types.
They could make a relationship real toxic.