In the case of San Antonio & Aransas Pass Railway Company v. Wagner, 1915, the U.S Supreme Court ruled in favor of Wagner. The dispute arose when a train owned by the railway company hit and killed two mules belonging to Mr. Wagner on an unfenced section of its track which ran through his private property in Texas. The court held that under Texas law, it was incumbent upon railway companies to fence their tracks where they crossed private lands not purchased or condemned for right-of-way purposes; failure to do so made them liable for damages caused by their trains hitting livestock straying onto such sections from adjacent landowner's properties. This ruling affirmed that state laws requiring railroads to fence their lines were constitutional and did not violate due process rights under Fourteenth Amendment as claimed by the railroad company.

In the dissenting opinion for the case of San Antonio & Aransas Pass Railway Company v. Wagner, it was argued that the court majority had erred in its interpretation and application of legal principles related to negligence and liability. The dissenting justices believed that there were significant factual disputes regarding whether or not the railway company had acted negligently, which should have been resolved by a jury rather than decided upon by judges. They also disagreed with how causation was determined in this case, arguing that even if negligence on part of the railway company could be established, it wasn't clear whether such negligence directly caused harm to Mr. Wagner's property as claimed. Furthermore, they contended that certain evidence presented during trial proceedings may have been improperly admitted or weighed too heavily in influencing decision-making process at lower courts - an issue they felt warranted further examination before rendering final judgment.