This is the only part of the text where the English diverges in meaning from the Greek, i.e. the Greek and English are saying different things.  The Greek text gives two possible behaviours (remain silent or admit ignorance) which are preferred to a third (getting the answer wrong).  The English text suggests that the first behaviour (remain silent)  is preferable to the second (admit ignorance).  How could you amend it so that it says the same as the Greek?