As a "good witness" I would never give even the slightest credibility to anything said by one who had left the org, especially one who displayed the cliché "apostate" tendencies.
The best result comes from a casually dropped, calmly spoken, BRIEF, sentence.....that encourages the mind to dwell on something.
One lady who had left simply said a sentence to me once that was similar to the famous Aldous Huxley quote: "Facts do not cease to exist just because they are ignored"
That stuck with me.....