LHR-AUH-MCT, heard it on about three different flights, possibly with the same mixed fleet arabic speaker (certainly was the same chap on two flights).

But I think we've answered the question, that there is no linguistic reason for a change, and the pronounciation should be possible. If I hear it again I shall strike up conversation with the person in question and see if they said what I think they said! It is highly possible that my hearing is defective.