Under a general denial, the defendant was entitled to present evidence that the plaintiff caused her own injuries, because this defense constitutes a set of facts inconsistent with the defendant's liability. Robin Mulcahy commenced this medical malpractice action against Gary Hartell, D.C., a licensed chiropractor from whom she sought acupuncture treatment, alleging that he was negligent in several respects including in failing to utilize "clean needle techniques," which led to the introduction of bacteria into the wounds caused by acupuncture needles. The plaintiff alleged that she developed cellulitis where the needles were inserted and was hospitalized. She allegedly required intravenous antibiotic treatments and experienced permanent scarring. The defendant filed an answer denying the claims of malpractice but did not assert any special defenses. The plaintiff filed a motion in limine to preclude evidence of her post-treatment conduct claiming that the defendant had not pleaded comparative or contributory negligence pursuant to Practice Book §10-53 as a special defense. The trial court denied the motion. The defendant presented expert testimony that the plaintiff's cellulitis was caused by her wiping the skin with an unwashed hand or unsterile object in her car after the acupuncture treatment. The jury found that the defendant violated the relevant standard of care by failing to observe clean needle techniques, but that this violation did not cause the plaintiff's injury. The plaintiff appealed claiming that the court erred in denying her motion in limine. The Appellate Court affirmed the judgment. The decisive issue was the distinction between cases in which the defendant asserts that the plaintiff has been comparatively negligent, and, thus, the defendant's conduct could also be a proximate cause, and those cases in which the defendant claims that his conduct did not cause the plaintiff's injuries at all. An assertion of comparative negligence is consistent with the plaintiff's rendition of the facts and must be raised as a special defense. The claim that an actor other than the defendant caused the plaintiff's injuries is inconsistent with a prima facie negligence case, and, thus, can be pursued under a general denial. The essence of the defense in this case was that the plaintiff was entirely responsible for her injuries; therefore, the court correctly admitted the evidence without the assertion of a special defense.