Once you've blown a disc, it's blown. (by "blown," I mean herniated, not bulging). Sometimes, in a few cases, you *can* have a herniated disc, but no leg pain/numbness.
If that person is moving the wrong way (stiff, or just plain inflexible to begin with, putting increased stress over the area he just injured), the symptoms can come back with avengence.
Simple clinical tests can be made If the spinal cord is pinched by the bulge in the disc surgery works.
True. I see it all the time. The "company" doc is trying to save $$, and takes short cuts. Unfortunately, there's that one time he does, and it ends up costing the insurance company (not to mention those like your friend) a lot more.