The Imitation Game, a biopic of Cambridge mathematician Alan Turing who cracked the German 'Enigma' code in World War II, has opened strongly in Britain and the United States, and begins here on January 1. Between Benedict Cumberbatch's brilliant performance as Turing, and Eddie Redmayne's portrayal of physicist Stephen Hawking in the biopic A Theory of Everything, the Brits think they've got the "Best Actor" Academy Award wrapped up one way or another.

Vanity Fair seems to be working Redmayne's corner. It recently gave both men a full-page colour photograph each in a spread titled "The History Boys". But Redmayne got a half-page shot on the contents page as well, smiling winningly in double-breasted tweed jacket astride a bike with a Jack Russell terrier in its basket. If that's not Vanity Fair editor Graydon Carter trying to swing voters Redmayne's way, I don't know what is.

But the latest volley appears on the New York Review of Books blog – the short version of an about-to-be-published essay on the The Imitation Game by Christian Caryl who edits Foreign Policy's Democracy Lab website. A trilingual Yale graduate and career journalist, Caryl's curriculum vitae has "intelligence community" written all over it. He is a former Newsweek Moscow bureau chief, was a freelance journalist in Germany for 13 years and, intriguingly, served as deputy-director of the Kazakhstan Institute of Management around the time Kazakhstan achieved independence from the USSR. You join the dots.

Caryl may have stared down scarier people than Harvey Weinstein in his time but I still wouldn't want to be him when Weinstein reads his piece on The Imitation Game. Think Vladimir Putin reflecting on US economic sanctions while watching the rouble plummet - that's the mood Harvey is going to be in. The Weinstein Company bested a gaggle of bidders to win US rights to The Imitation Game and will get the credit if the film wins Oscars. That's why Harvey bought it, and what Harvey wants at the Academy Awards he likes to get.

Caryl's New York Review blog is headlined "A Poor Imitation of Alan Turing" and he attacks on two fronts. The first is that director Morten Tyldum makes a whole lot of stuff up. The second is that, while Turing's sexuality is central to the storyline, he is never actually seen kissing a man. "The Imitation Game is a film that prefers its gay men decorously disembodied," Caryl writes. "To be honest, I'm a bit surprised there hasn't been more push-back against [the film] by intelligence professionals, historians, and survivors of Turing's circle." Caryl suggests reading the Turing biography by Andrew Hodges instead of seeing the film.

Without knowing about Caryl's critique, The Imitation Game has a lot to offer beyond Cumberbatch's fetching performance. The film draws attention to a vital part of the history of World War II, movingly portrays Turing's childhood as well as his war years, underlines the stupidity of laws proscribing homosexuality, and features winning performances from Keira Knightley, Mark Strong and Charles Dance in support. Seeing a mathematician as hero is refreshing, and seeing Keira Knightley's Joan Clarke as a mathematician of comparable ability even more so. But Caryl's criticisms are important and cannot be dismissed. Why couldn't director Morten Tyldum and writer Graham Moore make an equally good film while showing greater fidelity to Turing's story?

A more sympathetic review of The Imitation Game in The Huffington Post by blogger Victoria Sadler underlines just how low the veracity bar now is in the biopic business. "The film has at times only a tenuous link to reality but that is often the challenge when turning fact into fiction," Sadler airily rationalises. She was "not going to get worked up" about the film's flaws, she says, because "it is a tough enough challenge for scriptwriters to frame reality into a workable plot structure".

There lies the paradox of commercial filmmaking. To get something on the big screen one has to worry about "workable plot structure", even if the result isn't faithful to the facts of a life. But compromise the facts to get the film made and one can bring far greater attention to a life story than would happen otherwise. "And I suppose if this leads to more people reading Andrew Hodges' biography or wanting to know more about Turing," Sadler writes, "I'll take that."