Yes. If he would have just answered the questions, as "humiliating" or "offensive" as he considered them to be, there would have been no issue. Those questions are asked for good reason, NOT just to intimidate, harass or to derive any thrill from. Don't like it, people are free to fly with another airline.
U.S. confirms ISIS computer expert killed in air strike (Reuters)
from the article: U.S. couple with Jewish roots didn't expect El Al's inquisition