In the case of Hetzel v. Baltimore & Ohio Railroad Company, 1897, the U.S Supreme Court ruled in favor of the defendant, Baltimore & Ohio Railroad Company. The plaintiff, Hetzel had sued for damages after a train accident caused by an alleged negligence on part of the railroad company's employees resulted in his injury. However, it was found that at the time of incident he was riding as a gratuitous passenger and not as a fare-paying customer or employee which would have entitled him to certain protections under law against such incidents. The court held that since Mr.Hetzel was traveling free-of-charge without any contractual obligation from either party involved regarding his safety during travel; hence he could not claim compensation for injuries sustained due to ordinary negligence on part of railroad company's staff.

In the dissenting opinion for Hetzel v. Baltimore & Ohio Railroad Company, it was argued that the majority's decision to uphold a lower court ruling in favor of the plaintiff was incorrect due to an error in jury instruction. The dissenting justices believed that there were two potential causes for the accident: one being negligence on part of the defendant (the railroad company), and another being an unforeseeable defect or failure in machinery. They contended that if both these possibilities were equally likely based on evidence presented, then it would be unjust to hold defendant liable simply because they could not definitively prove their innocence against all possible causes. This is contrary to established principles where burden of proof lies with plaintiff who must establish negligence by preponderance of evidence rather than mere possibility or conjecture.