The thing about the Direct Results mode is that the results go straight from craigslist to you. They are loaded in a new window where our code can't see them at all. (We're also not affiliated with craigslist in any way, and so don't have any special access to their listings.)
This means that you get exactly what you would find by searching craigslist manually. However, it also means we have no way to tell whether a given link has results or not, so we can't remove the ones that don't.
We will keep this request in mind though, in case circumstances change!