As he deals with the awful burden of esophagal cancer spreading through his lymph nodes, he is concerned about rumors of a death bed confession. He is trying to make clear to us what he believes before he is incapable of doing so later-on.
Despite that over-arching political concern, Hitchens' first real philosophical assumption is that the universe exceeds in complexity, full human understanding. And so, uncertainty is inescapable. He did not discover the principle, he must concede to it. He also concedes the possibility of a prime mover.
Atheism is too certain a position for Hitchens, author of the badly titled book God is Not Great. Badly, because it is too declarative, and certain. Where God is a wide-open term used to short-hand the ineffably complex universe, calling it "not great" is the equivalent of saying life is a half-empty glass. He just does not have access to enough information to make that determination.
Source: Irish Central
Here we find a number of popular falsehoods from Brendan Patrick Keane, like that atheism requires certainty and that atheism and agnosticism are mutually exclusive. Refutations of these myths are easy enough to find for anyone who spends more than a few seconds researching them. So either Keane didn't bother because he assumed he knew all he needed or he did the research and is deliberately misleading his readers. Both reflect very badly on him.
The quality of Keane's reasoning is revealed by his objections to the title of Christopher Hitchens' book God is Not Great. Keane's complaint is based on the premise that there really is a "God" which Hitchens was writing about but which we can't know much about -- a premise which Hitchens, an atheist, obviously doesn't share. From Hitchens' perspective, he was writing about a fictional character and we have more than enough information from all the stories to make a declarative, certain conclusion about the nature of that character: it is not Great.
Keane could have avoided all his errors if he had simply done a little bit of research on the subject -- and since the nature of atheism is absolutely central to an article about whether or not a person is an atheist, there's just no excuse for not doing that research. At the very least, he should have been expected to double-check some basic facts; by not doing so, he expresses what I consider to be a callous disregard for the truth. When you stop caring about what is true or false and just go with whatever is most convenient or whatever is most consistent with your preferred ideology, your statements should be treated as lies rather than mere mistakes.
Brendan Patrick Keane is described as "a writer and illustrator" who is "passionate about the Irish heritage of NYC." It's a pity that he also isn't equally passionate about the truth and getting his facts straight.