He was real worried..
The interview started on a very casual note as the officer asked him some question about his home country and how the situation is etc, etc.
At first my friends did not put 2+2 together, then he realized that the officer was asking a lot relating to his green card application.
It seems after the first few minutes he said I need to get an additional file and left the room, then my friend looks the the file and immediately he saw his handwring on his Green card application, he immedialtly understood what the office was trying to get at.
He also said that in between he would suddenly be asked one history question like " So why did the Pilgrims come to America", "What was the name of their ship etc". He said that he was almost asked 25 history questions during his 1.5 hr interview.
He said that he almost felt that he would be rejected... finally when he was told you passed, he was elated.