As Sandy said off the bat, few if any scholars believe that Niles collected a version of "Judas" (Child 23) from oral tradition. In fact, few believe it ever was IN the oral tradition to begin with, as it was written down in English earlier than any ballad we know to have been sung. In other words it seems to have been written in a manuscript before the existence of the ballad genre in English. This does not mean it can't have been adapted into a ballad, but there is no evidence of that between Child's single manuscript copy and Niles's "collected" version.

Our guest from the Niles Center is of course valiant in attempting to defend Niles, but apparently can offer no firm evidence on the matter.