It looked that way until it was proved that the sample used for carbon dating was taken from a patch and not from the shroud material.
Actually it was a combination of original Shroud AND 16th Century patch material that varied from 60% to 40% patch depending on where on the original sample the sub-samples were cut. This resulted in the variation in dating reported by the three testing labs results in the four sub-samples tested which did not overlap in their degrees of confidence. THAT should have been a big red-flag that something was wrong.