Even as a fellow goy, I find it odd they mention gevalt only peripherally.
I think it was one of Leo Rosten's funny stories about a Jewish woman whose family changed their name, became Episcopalian, moved to Connecticut, and joined the country club.
One afternoon, lunching with her waspy ladies group, the waiter spilled hot soup down her cleavage. "Gevalt!" was out of her mouth before she could think. As all heads swiveled toward her, she added demurely, "Whatever that means."