Just consider that flight crewmembers have alot more stuff that the typical groundworker can work with.
Just because you see someone active at the beach, fishing or doing yardwork, doesn't mean they are ok to fly.
Then again if they are videotaped working as a bricklayer, or going down the black diamond ski slopes while listed sick with a back injury, most union members won't have a problem with the company sending the hounds after those in question.