Ortho doc says "I've never seen it happen"...
Saw the thread while at work with a Denver orthopedic surgeon (ironically getting ready to perform a shoulder stabilization)--asked him about the liklihood of seeing the two injuries simultaneously. He's never seen it in the twenty years he's been in practice (not that it's absolutely impossible-just highly improbable). He's reduced both shoulder and elbow dislocations in the backcountry (but he knows exactly what he's doing too). If it were me and I weren't paddling close to help and had an isolated shoulder dislocation (eg no clavicle fracture)-I'd be happy to get it reduced in the field (and then follow up with a doc when possible--we usually get post reduction x-rays except in habitual dislocators).