OK - that was shorthand for "individuals who present evidence that they need further scrutiny". Every day immigration agents make decisions about who they're going to take aside for any number of reasons - problems with documentation, odd travel history, flying AMS-LHR on a Sunday evening while being between 20 and 25 years old (been there!), I've seen reports that in at least one airport they watch people's feet while they're standing in line, you name it. Mrs. Milepig was once questioned when we flew the outbound together and she flew home by herself before me. They actually asked "Where's Milepig." To which she wanted to reply "I left him behind to fend for himself."

They're trained to sniff things out, and this couple passed the sniff test.

watching peoples feet? That is strange. I guess that they then will have the day with my feet. I cant still cause I cramp. I am always moving around.

A dog or a two-year old toddler would do no worse than the "trained" -- odds are the dog or toddler would do better than a "trained" passport control worker, especially one trying to watch feet at FRA or MUC.

Congrats with The Great Escape!

There's a tiny little chance this story bites back next time they fly into Terra Schengen. Any immigration vogon at any Schengen airport may pick up the overstay on his computer next time they fly in, and if he happens to have a bad day... It's still a good idea to make a Plan B for their next trip to Europe. I'd start with booking ample connection time to sort out things if needed. You probably don't need it, but you never know.

Good advice, Diabo. Thanks.
The whole thing went so smoothly. The agent hardly kept them long at all. I think they only had 40 min total in Frankfurt.