A "bloodless bullfight" in New Orleans - oh, sure, pal, we know what THAT was code for. You and Shaw discussed a "bloodless bullfight" - I think not, sir. It appears to me that Railroad Yard Guy has a bald spot and thus may be the gunman who Euins saw. Yep, that's it. Bloodless bullfight / Shaw / PO Box / bald spot = case closed.
I actually think these are two different people, but I will concede - wait for it - PROPINQUITY!