"Throughout the olam hayeshivos of the late 1940s and early 1950s, Rav Dov Schwartzman was spoken about with awe. There are numerous stories and legends of his greatness and of how Rav Aharon Kotler sought out a bochur who was a true gadol baTorah as a son-in-law. What is clear is that when Rav Aharon traveled to Eretz Yisroel and delivered shiurim there, Rav Dov’s incisive questions and insights, and the fiery Torah debates between them, made such a profound impression on Rav Aharon and convinced him that here was the gaon and ilui whom he was seeking."
I heard the following from Rabbi Rakefet regarding Rav Aharon's decision to have Rav Dov as his son-in-law.
Rav Aharon gave a shiur at Chevron Yeshiva. All were very attentive to his brilliant Torah analysis - except for one. There was a bachor sitting in the back who seemed bored and inattentive - sitting with his feet propped up. Rav Aharon angrily walked to the back of the room to confront this arrogant young man. [Rav Aharon had a deep impatience with anyone who was not interested in Torah - especially to his own insights which he had worked for hours to understand properly. My brother who learned in Lakewood under Rav Aharon told me that he had a special briefcase to carry his chidusshim. When he was finally given permission to leave communist Russia with minimum belongs - he personally carried that briefcase. At the border he was stopped and the official perused the papers and asked him whether they were state secrets. When Rav Ahron told him it was Torah chiddushim - the guard laughed and told him he could keep the "nonsense" and cross the border to freedom. Rav Ahron was furious and started yelling at the official for his chutzpah and contempt for Torah. Fortunately there were others who quickly got him past the check point - or he problably would have been sent to jail or worse.] Rav Aharon stood over the bachor and demanded to hear what he thought of the shiur. Rav Dov nonchalantly replied, "The Kletzer is a great Torah genius - but his shiur is based on an error. He forgot an explicit mishna." Rav Aharon fainted from the shock and when he recovered said -"that is the one I want as my son-in-law."