I’ve been in this position a couple of times w airport security, none ever found anything and they never offered an apology for the “inconvenience.” 

I was actually arrested once in a routine traffic stop because the cop claimed he ran my license and it came back as suspended.  Sat in jail overnight only to ultimately prove my license was free and clear after paying to get my vehicle back from the tow truck. Didn’t matter at the time and ultimately carried an arrest on my record for 7 years based on nothing…always guilty until proven innocent.

They will do whatever they want, whenever they want. It’s certainly eye opening about how few “rights” we actually have when things like that are going down.