Same thing happens to me, every single time I travel alone.
Once they told me they found a metal object in my bag that looked like it might be (used as) a weapon. It wasn't, but I could understand it might look that way on the scan. But as I was in a foul mood from being searched twice already I thought well it's your job, you go and find it. I was stunned when they gave up after a few cursory glances in the wrong pockets, and discretely left the offending object in the waiting area before boarding, along with a sarcastic note.