The Smithsonian article doesn't actually say why Falk and Wade believe the relevant words are a scribal error. It just says the scribe had an "unsteady calligra

The Smithsonian article doesn't actually say why Falk and Wade believe the relevant words are a scribal error. It just says the scribe had an "unsteady calligraphy", though looking at the manuscript I disagree with that assessment (the hand is steady and clear). And in any case, Falk and Wade don't argue that the issue is a sloppy hand, but rather that the scribe was unfamiliar with non-Latin letterforms, namely wyn and thorne. They identify two errors the scribe made, and also support their new reading by looking more thoroughly at the surrounding sermon (e.g., it talks about wolves and sets up a comparison just before the quote from Wade).