There's a guy in Texas who has been fined $10,000 because he left the screening area, and the airport, when he refused to get felt up. The rule, according to the TSA, is that once you have entered the screening area you MUST be screened to the satisfaction of the TSA. No leaving. No backing out. We agreed to this, they say, when we bought our ticket.
If that mother had protested too much or pulled her kid out of the screening, the goons would have been all over her. Talk about traumatizing a kid. She did what she could do given the circumstance.
Next time, she needs to drive.