This is jackass reasoning for the DNA test offered by know error. Mislabeling of the biopsy tissue by the original pathology lab is subject to a very small possibility of error. Drawing a patient's blood for white cells to perform DNA fingerprinting is also fraught with possibility for error. Adding on an additional outrageously expensive test to confirm that no error occurred during prostate biopsy specimen collection or processing is crippled by the fact that additional preanalytical labeling errors can occur for this additional genetic testing as well. Let's say the blood tube collected for DNA fingerprint comparison gets mislabeled and mixed up with another patient's blood tube. Then a patient gets a discordant result using the "know error" DNA fingerprinting test, when the biopsy tissue is truly their own.
This abomination of a test may represent the very apogee of outrageous, expensive, and inefficient diagnostic testing advocated by greedy physicians and businessmen who benefit financially from excessive, medically unnecessary testing. It figures that a smarmy urology group that profiteers off of performing mountains of medically unnecessary lab testing came up with it. What a joke.