I have been wondering, though, whether there were any academic consultants involved with the film. Like many films of the day, the credits all appear at the beginning and they are not detailed. You're lucky if all the major actors are credited, let alone members of the crew. There are no dolly grips or caterers here! Nor does IMDb's entry help here.
Happily, my friend Peter Groves has been in touch with me this week to let me know that in fact Professor George Kilpatrick was employed as an academic consultant on the picture and even visited the set in Spain. Armed with this knowledge, I noodled around on the net a little and found one or two mentions of this fact, including a Variety Review from December 1960 and a recent article by Tony Williams ("Nicholas Ray's King of Kings", CineAction 76 (Spring 2009)). Williams writes:
Ray and Yordan worked on the screenplay with Catholic Oxford Don the Reverend George Kilpatrick who remained on the set during filming. Ray expressed his indebtedness to this scholar in a letter to Samuel Bronston.Williams does not give his source for this item, but I'd love to see it, or anything else that details Kilpatrick's involvement.
Update (Sunday, 3.42pm): I am grateful to Matt Page on Twitter and Stephen Goranson in comments for their help in pointing to Williams's source for the above information. It is Bernard Eisenschitz, Nicholas Ray: An American Journey (translated by Tom Milne; London: Faber and Faber, 1993): 363:
Meanwhile he [Ray] continued working on the script with Jordan and a Catholic priest, the Rev. George Kilpatrick, an Oxford don, who remained on hand throughout filming. In February, he wrote to Bronston to say that, thanks to Kilpatrick, he had solved the dramatic problem of how to treat the trial of Jesus. ‘For the first time since I completed the script of Savage Innocents, I feel like writing again.’
Williams does refer to this book in his footnotes, but not in the precise location where one sees the above quotation. I wonder if Williams' paraphrase of Eisenschitz slightly over-interprets it when he says Kilpatrick "remained on the set" during filming. We know that Kilpatrick visited the set but to "remain on hand" during filming may mean that he was available and in contact throughout, e.g. at the end of a phoneline, but I would be interested to hear more.