>They don't guarantee that the term you quoted will be in the results.
They do guarantee it. Sometimes Google is buggy and messes up in determining what's page is actually visible on the page compared to just being somewhere in the HTML.
That's a loose definition of guarantee, I think. They know what's on the page because they include a brief summary in the results, but even there quoted terms don't always appear.
Here's an example someone posted a few months back where google decided the user didn't really want what they said they wanted:
They do guarantee it. Sometimes Google is buggy and messes up in determining what's page is actually visible on the page compared to just being somewhere in the HTML.