Spirit, that is not real unusual. I traveled every week for almost 10 years. I had both hips replaced and before they had the walk in machine, I had to do pat and wand. Even though I knew most of the TSA screeners by name and went to dinner with several. The boss lived down the block from me. They still had to do the “bomb” test swab on me on occasion. I truly was so used to arms out, palms up, etc. Wait for the cotton swab to come out of little machine. You were probably just random. But, they were doing this to me over 15 years ago.
I figured it was probably random, but the intrigue makes a better story. LOL And I haven’t flown since 2009, I think.