The opinion of epistemic superiors as evidence for/against theism?

[X-posted at Prosblogion] A few months ago, I met a grad student who has a prominent philosopher of religion (X) in his department. The graduate student was a theist when he started grad school, but soon realized that this is a minority position in philosophy. Disparaging remarks about theists (and specifically Christians) fueled his insecurity. Although there are no longitudinal surveys on this, it seems that atheism increases as people climb the academic ladder. For example according to the PhilPapers survey, in philosophy, only 14.6% of philosophy faculty believe in God. When postdocs are included, this percentage rises to 16.3%. Graduate students have the highest percentage of theists, 20.8%. So it seems plausible to me that at least some graduate students lose their faith as a result of the majority opinion in academia.

As the graduate student and I discussed X and what a brilliant scholar she is, the graduate student said that one important reason he is still a theist is the fact that X is a theist. He said "X is one of the smartest academics I know. The fact that X is a theist, even though she considered counterevidence carefully (like the problem of evil), constitutes strong evidence for theism for me, and for me it's a good enough reason to remain a theist". Is the graduate student rational?

Now, treating X's opinion that p as evidence for p is not as problematic as it may seem at first. Given the importance of the evidential force other people's opinion in recent social epistemology, it does not seem all that implausible. Although we should not straightforwardly defer to the opinion of others, even epistemic superiors, it seems rational to accord at least some evidential weight to their views.

However, there are many smart academics who are not theists. Purely percentage-wise, our graduate student, were he to adopt the principle "Accord some evidential weight to the beliefs of epistemic superiors" would find his opinion swamped by the majority of non-theistic academics. But the graduate student does not statistically aggregate opinions of others. Rather, he takes *X's beliefs* in particular as evidence for theism, at least as a good enough reason to remain a theist.

My question is: is the graduate student being rational, and if so, on what basis? I am thinking of the following suggestions: 

1. He knows X's work and views really well, so he can better assess the reasons why she is a theist and does not have this access to other academics' religious opinion. However, if this is his heuristic, it is not quite clear why the *opinion* of X, rather than straightforwardly going for the reasons for why she holds this opinion, should count as evidence? Can't he evaluate those reasons independently of her opinion?
2. X is already a theist, and, at least under some epistemological views (e.g., Kelly's belief polarization paper) it seems not unreasonable to pay more attention to evidence that supports one's views. X's opinion might carry much weight in the graduate student's total body of evidence that is significant for theism. 
3. X has turned out to be a reliable guide to justified true beliefs in other domains for the graduate student, so in the absence of other information, it is not unreasonable to also trust that her theistic belief is justified. 

It seems that in everyday life, we do treat the opinion of some people as having more weight than the aggregated opinion of the community. Such people are typically epistemic superiors, i.e., people whom we think of as smarter or better-informed than we are. I am wondering if doing so is justified, or just a form of biased reasoning (confirmation bias, misleading vividness etc).