An oncologist is a medical doctor who specializes in the diagnosis and treatment of cancer. Some oncologists treat patients with all forms of cancer, and others specialize in only one type of cancer. Medical oncologists - These physicians treat cancer with medications including chemotherapy, targeted therapies, immunotherapy, and coordinate other types of treatment.
Definition of Rebuttal. Strictly interpreted, rebuttal refers to an attempt to disapprove, contradict or argue to overcome an opposing reasoning or evidence by introducing another reasoning and evidence to destroy the effect of the previous one.
Bob's defense that he did not make the statement is not a truth defense; it is rebutting the assertion that the statement was made at all. The defense of truth in defamation claims means that the asserted statement assuming it was made was true. In your example, that issue never really arises because the complained about statement is one of opinion, not of fact.