In the 1931 case of St. Louis Southwestern Railway Co. v. Simpson, the U.S Supreme Court ruled in favor of Simpson, who was representing her deceased husband's estate as administratrix. Mr. Simpson had been killed while working for the railway company due to a faulty car coupler that failed to connect properly and caused him to fall under moving cars on two separate occasions within a short period of time; he died from his injuries after the second incident. The court held that under Federal Employers' Liability Act (FELA), an employer is liable if their negligence played any part in causing an employee’s injury or death, regardless how small it might be compared with other causes contributing thereto; this includes situations where multiple acts of negligence combine to produce such harm but no single act alone would have done so. Furthermore, they clarified that when determining whether there has been contributory negligence by an injured worker which could reduce damages awarded against their employer under FELA - i.e., if worker's own carelessness also contributed towards his/her injury/death - courts should consider all relevant circumstances including those related not just directly but indirectly too like habits/conditions affecting person's capacity for self-protection etc.; thus rejecting railway company’s argument here about alleged contributory negligence by Mr.Simpson himself.

In the dissenting opinion for St. Louis Southwestern Railway Co. v. Simpson, Justice Stone argued that the majority's decision to overturn a jury verdict in favor of an injured railway worker was inappropriate and inconsistent with previous court rulings on similar cases under the Federal Employers' Liability Act (FELA). He contended that it is not within the Court’s purview to decide whether there was enough evidence presented at trial to support a finding of negligence by the railroad company; rather, this should be left up to juries as fact-finders. Furthermore, he disagreed with their interpretation of FELA which seemed too narrow and contrary to its purpose - providing broad protection for workers against injuries caused by employer negligence or unsafe working conditions.