I'm looking to see how I can implement search exceptions like this.

For searching a single thread, the option appears (I believe) when there's 3 or more pages in the thread. It's in the yellow bar at the bottom of the thread, where the page links are.

You could also put part or all of the exact thread title in quotes, then make search to search by post vs thread. This won't guarantee only that thread shows up, but they should sort out to the top of the list since hits in a title are weighted higher.