Negligence under the Jones Act is a cause of an injury if it played any part, no matter how slight, in bringing about the injury or damage, even if the negligence operated in combination with the acts of another, or in combination with some other cause.
Comment
See Ribitzki v. Canmar Reading & Bates, Ltd. Partnership, 111 F.3d 658, 662 (9th Cir.1997) ("even the slightest negligence" is sufficient to support a Jones Act finding of negligence) (citing Havens v. F/T Polar Mist, 996 F.2d 215, 218 (9th Cir.1993)). This test is often described as a "featherweight causation standard" and allows a seaman to survive summary judgment by presenting even the slightest proof of causation. Ribitzki, 111 F.3d at 664.
The causal requirements for Jones Act negligence and under the doctrine of unseaworthiness are different. See Lies v. Farrell Lines, 641 F.2nd 765, 769 n.7 (9th Cir.1981). Separate causation instructions, therefore, will be necessary where both claims for relief are asserted.
BS&J NOTE: The featherweight causation standard is a critical legal standard used by experienced maritime lawyers in all phases of a Jones Act injury case. There can be multiple causes of an accident under the Jones Act, and so long as the employers negligence was a cause of the injury, no matter how slight, the employer is liable for damages. Various cases attempt to limit the expanse of this causation standard by claiming a preexisting condition would have naturally progressed. In the cases of preexisting conditions, the employer has the burden of proof to show that the condition would have inevitably worsened, and to what degree. This is a very difficult burden to meet in many cases. See Mauer v. U.S. 668 F.2d 98 (2nd Cir. 1983)
