I am answering this late for posterity.
No. Without hacking, you cannot obtain any shiny shadow Pokemon in XD. Unlike Colosseum, which allowed shiny Pokemon due to a bug that, I believe, checked the value of the trainer who had the shadow Pokemon and compared it to its own to prevent shininess (therefore making it ineffective), XD correctly checks YOUR trainer shiny value and always calculates it so it won't match.
A bit lame, but that's how it is.