I've listened to the recorded phone conversation, I've read the discussion and I've changed the english translation in "for fuck's sake!". While "cazzo" correctly means dick or cock in italian, in this case is used as an exclamation or an insert (Italian people often use different genitalia words in their slang and dialects to mean something amazingly good or bad). In this case, "for fuck's sake" could be a good translation, along with just "shit!" or "damnit!". I absolutely do not agree with "dickhead" since that one is widely know in italian as "testa di cazzo" referred to Schettino personally and not to the issue, like the tone and the small pause in the audio suggests.