Here are some questions... Are any of the UAX gates at ORD staffed by non UA personnel...SkyWest etc? The crew of 4 would be indicative of an express crew, so are they scheduled differently than mainline? I believe they are. If so to either questions, does that change anything in this situation? Surely a crew positioning trip is a given, but was some of this sloppy typical UAX crew scheduling? I've seen more than once less than stellar UAX crew schedule mishaps. If the GA was a UAX contractor, was training a factor? Just speculating here.