It has been doubted and tested extensively. That is why we know that no other theories hold water; not only does the one idea work, but none of the others do. It is skepticism and rigorous testing that is the heart of the scientific method, and it is through such trials that we have the confidence in the current theories- they have stood the test of time.
Until something new comes along. It's happened before. Something has been tested countless times and is supposedly been proven, and then something else comes up that completely disproves it. We believe we have the technology now to accurately prove the true, but the more we know about our world, the less we do. Just about everything scientists have come up with is simply a theory, so there's always a possibilty it can be disproven.
So, this is how I view the dragon deal. I believe humans and dinosaurs existed at the same time, but possibly in different areas. Look at the tale of Noah. Before the flood, there was a large pocket of water around the earth that created dew as awell as protecting the surface from harmful UV rays and the such. After the flood, that pocket was broken, and therefore, everything was subject to the suns rays. If you read biblical refrences, people began to get younger and younger after that time. What's to say this did not also affect animals, including dinosaurs. Being unable to grow as old could make them smaller, as well as humans which would have persistently hunted these things.
Anyways, it's unlikely that people would have called these large reptiles "dinosaurs". "Dragon" would have fit the discription better, and there have been past records on "dragons" that actually defined that of a dinosaur. One example was a town that had become famous for slaying a "three-horned dragon".
Over time, they would have been hunted more and more and died off slowly.
Well, anyways, I'll just say...
DRAGONS ROCK!!!