I would think a single screener could not summarily get a passenger booted out of a program, I doubt they have that authority. They could file a report of some sort that, depending on the nature of the real or perceived passenger behavior or offense, could upon review by a proper authority result in loss of the Trusted Traveler status. I too wonder at what would even closely approach a significant enough event, or apparently maybe two separate events, that could provoke the described reaction. Generally I don't exchange much more than casual pleasantries, and sometimes not even that, with most screeners. DFW is a big operation with literally thousands going through security during a typical shift. Over a week or more that number would approach astronomical so to get noticed and remembered would be no small feat.