First, routine: did you pack your own bags? Have they been in your possession the whole time? And did anyone give anything to you?
Normal so far. Then, with God and perhaps 100 other passengers in line as my witness:
Where did you stay on your trip, sir? What hotels? Do you have receipts to prove it? We'll have to see those.
Where did you purchase your ticket? How did you pay for it? Can you prove that?
And he never received any explanation of why he received a higher level of scrutiny than any other passengers. Oh, and it goes without saying that he's not a terrorist or dangerous in any way, other than that he's a TV writer.