Two Sentences, One Term?

A man was convicted twice, eight days apart, of breaking the national liquor ban. One conviction was for conspiracy and carried two years in a federal penitentiary. The other was a lesser offence and carried one year in a county jail. Neither written judgment said the jail term should wait until the penitentiary term was finished. He served the longer term and was released. Three years later officers came to take him in for the jail term. He said he had already served both at the same time.