Doctor who provided bad advice was too late in blaming the radiologist

Michigan has adopted a procedure whereby a Defendant who is sued can give notice to the plaintiff/victim and defend the claim by blaming someone else, even if that third-party is not legally responsible for the injury.  The Defendant is required to notify the plaintiff  of the claimed third-party fault on a timely basis, however, basically within 90 days of answering the suit or promptly upon learning of the culpable third-party. When Margaret Snyder's doctor identified a mass in her uterus, she sent Snyder for an ultrasound.  The radiologist apparently mis-read the ultrasound and concluded the mass was benign.  On that basis, no further treatment was recommended.  After more than a year's delay the mass was ultimately found to be malignant, and Ms. Snyder's survival probability was reduced from greater than 90 percent with prompt removal of the mass pursuant to the standard of care,  down to 15 percent:  In other words, she was moved from the ranks of almost certain survivors to almost certain fatalities by the doctor's neglect.