The scientists accurately dated what they were given. They dated a sample that was taken in violation of the protocols that had been agreed on—a sample that now turns out to be a melange of old and newer material, that when accurately dated, reports an average of the ages of the older and newer material which accidentally fell within the range the skeptics expected.
Bad sample in, bad data out.
This is factually incorrect and doesn't even map to the excuse Rogers gave. It has been demonstrated that "melange" wouldn't have produced the date that was arrived at. Rogers claimed that the whole sample was from the 14th century and was a later invisible patch. He claimed that Gonella gave him threads from the middle of the samples tested. This is a lie. No threads were missing from the samples. There is no provenance for the alleged threads. No one saw Gonella take them. No one knew of their existence, and Gonella and Ricci had been ordered to return all samples to the Vatican before Rogers did his alleged tests. The Raes samples he said he had were stolen property. All of the samples taken at that time were supposed to be returned to the reliquary. Rogers was a fraud and a thieif.
Then what is the age of the shroud?