Obviously something was funny about that, and I think you hit the nail on the head with the foot fetish analysis...
You did take your grievance to the airline you work for and the TSA???
Ridiculous stuff like this happened with TSA all the time. I remember a crew member who was late for a briefing and showed up absolutely furious... the screener, a twenty-something woman, had stopped her to look through her crew bags, pulled out her makeup kit and even went so far as to open her eye makeup compacts and unscrew the lid to her mascara - like she was shopping instead of doing a security check. She held her up for 15 minutes. They harassed crews relentlessly following 9/11, and at LAX they would let ramp and catering employees walk around security. That was still going on when I quit a few years later... I heard they finally stopped allowing that.
The union was always telling us to report stuff like that and we did and nothing ever changed. Our union was completely worthless. They were good for taking $40 out of your paycheck and giving it to the DNC and that was about it. After I left that job I swore to never be a union member again and so far I’ve lived up to that promise.