I agree,
however there probably is no one-liner that fits all.
It's hard gettin' beat down, it's human nature to want to kick back , but it's part of being in biz.
The concept of using one's force against him/her as in karate can be applied verbally here, but you've only that one moment to spit it out to these types. So you have to 'feel' them out with that sixth sense we all like to cultivate.
His attaire, living conditions, eye contact, ability to grasp and rebut details, handshake, even how he cares for his dog ( you can tell lot's from how people keep their animals) all contribute to the sum content of a response.

Me...
i'd challenge him to a 'double-or-nuthin' flip
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