When the labs got their samples, they did not properly document their samples with photographs. Also, during the pretreatment, no labs had reported their samples contained contamination or how much there were. So, all the labs were not rigorous in carrying out the initial steps of the dating.
What is surprising to learn is that, once they had brought the vials back to their respective labs, very little scrutiny of the sample was carried out. Not one lab photographed the samples they received properly, i.e. both sides and with a scale. The samples were examined under a microscope, and a few alien fibers picked out, but no lab reported anything suspicious, even though later a STURP chemist found that threads from the adjacent Raes sample had high levels of aluminum, a high occurrence of cotton fiber intermingled with the linen, some kind of coating or encrustation, a high degree of oxidation, and FTIR spectra markedly different from threads elsewhere on the Shroud. Certainly the labs were not in a position to know all the results of all previous investigations of the Shroud, but they could have consulted with STURP personnel, or they could have requested comparison fibers from other parts of the Shroud. The fact that they did neither indicates an over-confidence in their ability to date the samples through standard procedures.
As mentioned before, it was not a blind test, so it was obvious to the labs which sample was from the shroud. The primary reason they could identify it was the herringbone weave on the cloth. But, this could’ve been addressed by unravelling or shredding the samples. It’s not like they needed an intact cloth to test it because the AMS process would be burning the entire specimen.
Curiously, the official report justified it by saying it would make it more “difficult and wasteful”.
With unravelled or shredded samples, pretreatment cleaning would have been more difficult and wasteful.
I don’t know what this would mean unless there were a lot of contaminants or spurious material in the sample. But, how would they have known that before they sent it to the labs? And how difficult is it to do pretreatment to an unravelled cloth? What exactly would be wasted by pretreating threads?
Also, the lack of finding a herringbone weave cloth as a control is evidence this cloth could not have been medieval. We have no archaeological artifacts of any linen cloth with a herringbone weave from the middle ages.