In the case of Pierce Oil Corporation et al. v. Phoenix Refining Company, the Supreme Court ruled in favor of Phoenix Refining Company in 1921. The dispute centered on a patent for an oil refining process that Pierce Oil claimed was being infringed upon by Phoenix Refining. However, it was found that the patent had been obtained through fraudulent means and thus could not be enforced against other parties such as Phoenix Refining Co., who were using similar methods to refine oil products independently developed without knowledge of Pierce's patented method. The court held that if a party obtains a patent fraudulently or even innocently but with false suggestions and concealment of material facts, they cannot enforce this right against others who have used similar processes unknowingly infringing on said patents rights due to their independent invention or discovery thereof. This ruling set an important precedent regarding intellectual property law and its enforcement within industries where technological advancements are frequent.

In the dissenting opinion for Pierce Oil Corporation et al. v. Phoenix Refining Company, Justice McReynolds disagreed with the majority's decision to uphold a lower court ruling that found in favor of Phoenix Refining Company. He argued that there was insufficient evidence to support claims made by Phoenix against Pierce Oil regarding unfair competition and misrepresentation of petroleum products. Furthermore, he contended that the case should have been dismissed due to lack of jurisdiction as it involved matters related primarily to state law rather than federal law. The justice also expressed concern over potential harm caused by upholding such a broad interpretation of trademark laws and regulations, which could potentially stifle competition within industries if left unchecked.