If God gave the text to Moses via direct revelation, they're in the same boat. But I believe Genesis likely came about the way most biblical historical narratives came about. Per Henry Morris,
“Visions and revelations of the Lord” normally have to do with prophetic revelations of the future (as in Daniel, Ezekiel, Revelation, etc.). The direct dictation method of inspiration was used mainly for promulgation of specific laws and ordinances (as in the Ten Commandments, the Book of Leviticus, etc.). The Book of Genesis, however, is entirely in the form of narrative records of historical events. Biblical parallels to Genesis are found in such books as Kings, Chronicles, Acts, and so forth. In all of these, the writer either collected previous documents and edited them (e.g., I and II Kings, I and II Chronicles), or else recorded the events which he had either seen himself or had ascertained from others who were witnesses (e.g., Luke, Acts).