Originally Posted by
newlywedJ
...told them that since they did not leave Greece the entire time, it would be OK, but if they had been touring around it would have been a problem...
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.