I have not had access to a Bronson in a very long time, but I seem to recall his commenting on the verse after the one with the apple:

My toung is mine ain, True Thomas said,
A guidly gift you would gie to me [Etc.]

as an odd piece of irony which did not really belong in a folk ballad. I'm v. curious whether anyone knows more about that aspect; is it a question that much gets discussed?