Quite right - as a drama the film works very well, as a documentary (which it is not intended to be) it would fail. There was a spy at Bletchley passing information to the Soviets (who were, of course, our allies at the time) - but he was in a completely separate hut from Turing and it's unlikely that they ever met. Information gained by breaking Enigma often couldn't be acted upon directly, because to do so would immediately have revealed that Enigma could be broken - but I don't think Turing played any part in deciding how to use the information, he would probably have been one of the worst possible candidates to make such decisions.