What does "Why didn't she ask EBA" mean in Hyouka? At the end of the episodes involving the movie, 10-11 iirc, just before the ending credits there is the subtitled text "Why didn't she ask EBA?" which I don't understand.

This wast touched on at this Yahoo Answers link but did not help my understanding.

Is this a joke from the translator? If so, what does it refer to?
Each of the Hyouka novels has a Japanese title and an English sub-title (the English sub-titles are present in the Japanese novels - they are not the work of a translator). At the end of each episode of the anime, the sub-title of the novel that the episode was adapted from is displayed; for the movie arc, that's "Why didn't she ask EBA?".

The English sub-titles are mostly references to mystery novels and at the same time thematically relevant. 


The first novel, "the niece of time", is a reference to Josephine Tey's The Daughter of Time. The arc is about Sekitani Jun, whose niece is Chitanda.
The second novel, "Why didn't she ask EBA?", is a reference to Agatha Christie's Why Didn't They Ask Evans?. Indeed, the whole affair would've been resolved quickly if Irisu had had just asked Eba how the film was supposed to end.
The fourth novel, "Little birds can remember", is a reference to Christie's Elephants Can Remember. The thematic relevance of this one is unclear to me.
The fifth novel (not animated), "It walks by past", is a reference to John Dickson Carr's It Walks By Night. I haven't gotten around to reading this volume yet, so I don't know what thematic relevance exists, if any.