Hilarious. The FBI has no need for anyone to confirm what shirt Oswald was wearing that day if, as you suggest, the fibers don't have evidentiary value. They already know that the arrest shirt belongs to Oswald because he is wearing it when arrested. They already know that the fibers are found on the rifle. To the extent that the fibers are being used to link Oswald to the rifle, there is no need to have a witness confirm that he wore the shirt that particular day. And if Bledsoe is not being coerced and Oswald wasn't wearing that shirt on the bus, then there is a significant risk that she confirms he was wearing a different shirt. Why would she say otherwise? Again, however, it makes little difference what she says either because there is little value to the fiber evidence or because fibers from Oswald's shirt could have gotten on his rifle on a prior occasion.
I've been quite sick of late, fellas, but I started looking at the forums again a few days ago and this thread caught my eye. While Richard makes some good points, he is clearly incorrect on one point. He claims the FBI could have dismissed the fiber evidence altogether, because there was no evidence the fibers on the rifle were added to the rifle on the 22nd.
But there was such evidence. The FBI's fiber expert, Paul Stombaugh, testified that the fibers were on top of the fingerprint powder. Well this strongly suggests the fibers were added AFTER Lt. Day dusted the rifle, and was unable to find any prints beyond the trigger guard prints, which he would later claimed were too smudged.
So, yeah, on the night of the 22nd, it was imperative that the DPD find some way to link Oswald to the rifle. They then sent the rifle to the FBI, who--by golly--found fibers from the arrest shirt on the rifle. Oh my. Now that's quite the coincidence.