They do that all the time
I flew from Budapest to Tegal two years ago and none of the bags arrived. We waited one hour in baggage claim before an old man came and told us to go to the service office. We all filled out a form, then I tried to call them to enquire after my luggage. No answer. Took a taxi back to Tegal to get my suitcase and learnt that they hadn't even entered my claim. I asked to go into their bag room to look for my bag but was told there were 500 bags in there. I got my suitcase 13 days later after a trip to Geneva with none of my suits to wear. AB then refused to reimburse my interim expenses. You'd think you'd be safer on a non-stop flight, but with Air Berlin change in Frankfurt or Vienna if at all possible.