No guarantee. Nog took the hit but when Heath went for him, Nog clinched his leg which indicates Nog was hurt but he wasn't totally gone as some would presume. That's the mark of a top level fighter, one who can take a shot and find a way to survive ala Fedor/Fujita.
Herring let Nog up. Nog was rocked BADLY and you know as well as I do that Herring could have finished it right there.
That kick was a good example of "getting caught". They had fought twice before, Nog won both. He also pretty much dominated their third fight too, except for that kick.