In the 1905 case of Texas and Pacific Railway Company v. Mugg, the U.S Supreme Court ruled in favor of the railway company, reversing a decision by the Texas Court of Civil Appeals. The plaintiff, Mr. Mugg had sued for damages after being injured while attempting to board a moving train operated by Texas and Pacific Railway Company as an employee. He alleged that his injuries were due to negligence on part of his employer who failed to provide safe conditions for work. However, it was found that Mr.Mugg himself had violated safety rules set forth by his employer which explicitly prohibited employees from boarding or alighting moving trains unless necessary for performing their duties - something not applicable in this situation since he was off-duty at time of incident . Therefore, it was held that contributory negligence applied i.e., Mr.Mugg's own actions contributed significantly towards causing injury thereby absolving defendant (railway company) from liability.

In the dissenting opinion for Texas and Pacific Railway Company v. Mugg, it was argued that the majority's decision to hold a railway company liable for injuries sustained by an employee due to negligence of another employee contradicts previous rulings. The dissent pointed out that in earlier cases, the court had established a principle known as "fellow servant rule," which states that an employer is not responsible for accidents caused by one employee to another during their work. This rule was based on the idea that when employees accept employment, they assume certain risks associated with their job including potential negligence of co-workers. Therefore, according to this view, Mr. Mugg should have assumed responsibility for his own safety while working on moving trains and thus cannot claim damages from his employer (the railway company) because he knew such risks were inherent in his line of work.