For thirty years W. Hall Harris III has taught on the faculty of Dallas Theological Seminary in the New Testament Studies Department. Since 1995 he has served as Project Director and Managing Editor for the NET Bible at bible.org passionately steering this revolutionary Bible from inception to global impact. Dr. Harris has traveled extensively in Western Europe, especially in Germany and Italy. And as an ordained minister he has served over the years as pastor of single adults, elder, and adult Sunday school teacher.
Could usage testing here be helpful, using native speakers and perhaps a questionnaire regarding how they would interpret the singular verb with the collective noun?
I'm relatively confident that most people would not intuitively follow interpretation #1 without some other external clues in the text that that was the case.