Rogers et al complained that the c-14 tests were not truely blind because the labs could tell by the 3:1 herringbone twill which piece came from the shroud. The samples were directly examined under microscopes by Vatican appointed fabric experts. You see things in the picture that they didn't. Besides, the Vatican has the Riggi sample. Why not just test it?
Rogers reiterated concerns about the protocols that were also stated by the scientists who did the tests. There was quite a search, conducted by Michael Tite of Oxford, trying to find matching weave and thread cloth to use as a control.
The simple solution would have been to merely pluck the samples and controls apart into threads, completely lacking weave. I don't know why they didn't think of it.
Yes, I and others see things they missed because they weren't looking for anomalies. They were looking for contaminants that were NOT part of the Shroud. They did not look at the threads of the sample itself. They were looking between the threads for things that didn't belong... not at the things they assumed belonged.
I agree that testing your so-called "Riggi Sample" is in order... and that is what Raymond Rogers did. He requested sample threads from the retained portion of the C14 test sample. He also examined threads from the Raes sample. His results falsified the data based on proving that the sample was not homogenous with the main body of the Shroud. Brown also requested threads from the control sample from the Shroud's custodian and confirmed Rogers findings using other techniques. Villareal has done similarly and also confirmed Rogers findings using yet different techniques.