Romney used a technique taught in counseling to help a person in denial/habitual liar to get in touch with reality.
First you repeat the statement they made (made by the liar), even asking them to repeat themselves.
Second you make nonthreatening statements: “You may be right” “That's an interesting idea!” etc. and you repeat the statement again.
Third you offer to help validate their ill perceived idea (It would expose the fact that it's not accurate)
Many times when you do step three they'll completely loose it...If prone to violence they may be dangerous.
The only thing Candy did was enable him, keep him from dealing with reality; thereby, keeping him from loosing it completely.....Maybe she saw something we didn't and/or is in the habit of defusing abusing situatios.