I have to rely upon second-hand accounts of how things went in the Q&A session which followed the Cambridge lecture. But I gather that His Eminence launched into lengthy and impassioned assertions of the the authority of the Magisterium. The answer offered to one questioner was the further question (asked in deeply shocked tones) as to whether those expressing doubts or concerns about Amoris laetitia perhaps failed to believe that the Pope was inspired and guided by the Holy Spirit in writing it. Thus the Magisterium was invoked not only in all its panoply, but in that crude form which, in the heyday of the old Catholic Evidence Guild, that Guild's speakers justly dismissed as being a misinformed Protestant or rationalist notion of what Infallibility means in Catholic theology.
More, later, on Cupich, Deo volente.