While what you say is true, the fact that he chose to address that issue among all the issues that plague us is telling. I can understand in a private conversation he might broach his disbelief, but not as the focus of a talk. He has revealed his, to my mind, crisis of belief. I know nothing of him, and his past proclamations would indicate whether this was anomalous or a continuation of his trouble with Catholic theology.
I know a lot of old people it is rare to find one that is 96 and still in possesion of all their reasoning faculties.