Is it possible to “sin ignorantly?”…

If we are to believe the words in 3rd Nephi, there must be a way to sin in ignorance, since it is cast as an option, even though the concept is obviously in error…

“Now they did not sin ignorantly, for they knew the will of God concerning them, for it had been taught unto them; therefore they did wilfully rebel against God.”

Book of Mormon, 3 Nephi 6:18