Although I'm SLF I am also a Licenced Aircraft Engineer so I am always very observant of Airline operations - especially when I fly with a carrier that I had not flown before with.
I had not flown with Air Berlin before and have not done so since, but I am 100% sure that the safety briefing was only in German (pre-recorded if I recall) and not repeated in English. I cannot remember the flight deck anouncements.
Must have been an oversight?
bizdev