The Supreme Court case May et al., Executors, v. Heiner, Collector of Internal Revenue in 1929 revolved around the issue of estate taxation. The executors of a deceased's estate argued that certain property transferred by the decedent before death should not be included in the gross estate for federal tax purposes because it was given as a bona fide gift and thus exempt from such taxes under applicable law at that time. The government disagreed, asserting that these transfers were essentially testamentary - made in contemplation of death - and therefore taxable. In its decision, the Supreme Court sided with the executors, ruling that there was no clear evidence to suggest these transfers were made in contemplation of death rather than as genuine gifts during life. Therefore they could not be taxed under existing legislation which only allowed for taxation on property transferred at or after death.

In the dissenting opinion for May et al., Executors, v. Heiner, Collector of Internal Revenue, Justice Holmes argued that the majority's interpretation of tax law was incorrect. He believed that a transfer intended to take effect upon death should be considered taxable under estate tax laws regardless of whether it is revocable or irrevocable during the lifetime of the grantor. According to him, such transfers are essentially testamentary in nature and thus fall within the purview of estate taxes. The fact that they may not technically qualify as 'gifts' does not exempt them from taxation upon death because their purpose and function align more closely with those of traditional inheritances than gifts made during one's lifetime. Therefore, he disagreed with the majority’s decision which held otherwise.