I've delt with similar situations in the retail business. I had a couple guys smoking at lowe's in the back, where the cameras weren't. I was the Mill Works manager, but I delt mostly with building materials as there wasn't a team leader so I was the faux morning manager for the department. I pretty much had to befriend the guys, not go 100% above their head and get them fired, but gently remind them our policies, and that they needed to go home, and if caught again blah blah. It would have cost me my job for not releasing them, and going above them. 2nd time. They got caught by the MOD(manager on duty) and just got sent home, and then drug tested 2 weeks later, so we could retain them as employees. At this point, I was thoroughly involved with their evaluations, and me not getting them fired, made it so they would work in a much more productive way when I was the manager, or when I had some sway in the area. It was super useful in getting our inventory done(bigggg deal in retail) and getting all the OT I could out of them.