A dog owner can be held liable for failing to stop an attack in progress, irrespective of whether he can be held liable under the one bite rule or any other legal theory.
Liability for failure to stop an attack is based on Restatement (Second) of Torts, section 518, comment (j) (1977), as set forth in Bushnell v. Mott, 254 SW 3d 451 (Tex. Supreme Ct., 2008):
Bushnell alleged that Mott was negligent not only in failing to keep her dogs restrained, but in failing to do anything to stop the attack after it had started. As a comment to the Restatement recognizes, the owner of a non-vicious dog is generally not liable for the former, but can be liable for the latter:
[A]lthough the possessor or harborer of a dog or cat is privileged to allow it to run at large and therefore is not required to exercise care to keep it under constant control, he is liable if he sees 453*453 his dog or cat about to attack a human being . . . and does not exercise reasonable care to prevent it from doing so.
See RESTATEMENT (SECOND) OF TORTS § 518 cmt. j (1977).
If we consider only Bushnell's original affidavit, Bushnell testified that while she was being bitten, she "never once heard [Mott] scold the dogs." Even if Mott did not know her dogs had dangerous propensities, Bushnell's original affidavit indicating that Mott did nothing to prevent her dogs from continuing to attack Mott raises a material fact issue concerning whether Mott failed to exercise ordinary care over her dogs once the attack began.
Failing to stop an attack in progress also can be used against the defendant at trial to increase civil and/or criminal liability. In the Diane Whipple case (People v. Knoller), defendant Marjorie Knoller was convicted of second degree murder upon proof that included (among other things) that she was present throughout the entire time that her Presa Canario dog was mauling the victim to death. See The Diane Whipple Case.