In the Doar Hayom daily newspaper, during the period of its being edited by Ze'ev Jabotinsky, a new item on the US Revisionist Conference was published at the end of January 1931.
Here is the story with the section relating to Betar enlarged on its background:
Can we presume were at this event two months later:
Dr. Magnes Chancellor of Hebrew University Called Traitor at New York Meeting: Revisionist Rioters
March 23, 1931
Stink bombs were thrown by Revisionists who had come in force to a meeting at which Dr. J. L. Magnes, the Chancellor of the Hebrew University in Jerusalem, delivered an address in Hebrew on the work of the University under the auspices of the Histadruth Ivrith, the Hebrew-speaking Association of America.
The Zionist Revisionist Organisation of America had adopted a resolution a few days ago before Dr. Magnes’ arrival here, demanding that the Council of the Hebrew University should dismiss Dr. Magnes from his position as Chancellor because of his “activities against Zionism since the riots of 1929″.
Dr. Magnes was called a traitor by the Revisionists present at the meeting and there was a real fight with fists between the Revisionists and the General Zionists who came to Dr. Magnes’ defence. After lasting for about half-an-hour the riot was subdued by the police, who with great difficulty ejected about 40 or 50 of the rioters.
Dr. Magnes then proceeded to deliver his address on the achievements of the Hebrew University, with occasional heckling by some of the Revisionists who had remained behind.
The riots started as soon as Mr. Ab. Goldberg, the Chairman, introduced Dr. Magnes. Dr. Magnes stood his ground calmly and apologised for being the cause of the unpleasantness. I am accustomed to being called a traitor, he went on. I have heard it before, alluding to the days during the war when he had been called a traitor because of his pacifism.
After the conclusion of the meeting, crowds of Revisionists’, who had collected in the street, hurled insulting remarks at Dr. Magnes, who refused, however, the offer of police protection, stating that he was not afraid and preferred to walk home alone.