Much the same here ... Ruby and I traveled together, and I waited by the 'other nationals' immigration desks. I could see that Ruby was being asked a few questions - then the immigration officer turned to me and called me over. The main problem seems to have been that Ruby did not have a return ticket - the reason being that she and I planned to fly back to Phils together on an unknown date about three months hence. Now, possession of a return ticket is not an absolute requirement, but many immigration officers will claim that it is - they, clearly, have not read their own guidelines!
After about five minutes further discussion Ruby was allowed through.
So, I think that they are just trying to establish your intentions, by asking some awkward questions.
