Camanche is probably right, it does seem like they were just trying to be fast about it.....but still.... it almost looks like hair is coming out of his abs or something....
My personal opinion is that Sephi had been in that materia soooo long that he was starting to degrade or something. Knowhatimean guys? I think that he may look like that because of his degredation process, but that wouldn't explain why his upper body is still intact..... hmm... maybe....

Wait wait! Invisible pants!!!!