But changing the word surprise is the job of the second draft. Not the first. In the first draft, you're telling the story, getting the foundation up and making sure it's stable and you have your point across. Using a thesaurus is like spackling the drill holes in your drywall, when you're not even sure you're going to keep that room.

He goes into further detail in On Writing. He also mentions a very good point. It's very hard to get your meaning across at the best of times. The first word you think of is usually the closest to your meaning, and a thesaurus quite often gets in the way.

Also as a edited version for your example. Instead of even using a Thesaurus.

When Stephen King saw her comment, he was very suprised that someone disagreed with him. In fact, that feeling stayed with him all day -- it surprised him just that much.
"Who was she to disagree with me," he said to his wife later, who mirrored his reaction.

Two surprises, less repetitive, and actually conveys the meaning without using the thesaurus. :D IMHO, the thesaurus is the crutch of the college student. Desperate to reach world length and show off their impressive vocabulary. It also helps to obscure the meaning when you're desperately trying to hide bullshit in pretty packaging.

I don't mean to sound like a now it all twat, lol, but I really don't think a thesaurus is necessary when careful editing clears most of the repetitiousness in a work.