Concepts of Evidence

Alan's skin has yellowed, so on Monday he sees the doctor, who examines him and declares that he has jaundice, i.e., the visible expression of an increased concentration of bilirubin in the blood (which I shall abbreviate as an i.c.b.). Some tests are made as a result of which on Friday, although Alan's yellowness remains, the doctor declares that Alan does not have an i.c.b. but that his yellow skin was produced by a dye with which he was working. On Friday which of the following propositions, if any, should the doctor affirm?