The carbon dating was botched. The piece of cloth used wasn’t part of the Shroud.
It was part of the Shroud we have today, just not part of the Shroud as originally made. The C-14 test sample was a melange of original 1st Century Flaxen Linen and Seventeenth Century cotton patch threads interwoven together to repair a worn corner using a technique called "French Invisible Reweaving."