Aww gee actualhealth. A bull in a china shop wouldn't stop thrashing about breaking things, so why should you?
2 separate doctors told Chris and his parents that he had advanced stage leukemia. Because nobody "wrote down" or particularly "cared about" which specific type, you choose to cast doubt upon the entire experience? The appropriate time for defending oneself is the point at which the attacks become ridiculous and relentless.
Unless Chris is indeed a liar, he had advanced stage Leukemia and your continued doubts are nothing short of obnoxious.