Answer:
You can easily refute the theory of evolution--just as easily as you can refute Newton's theory of gravity, or Einstein's theory of relativity. You just can't refute these theories using science or evidence with ease, as these theories are extremely well supported.
If you could confirm the existence of fossil bunnies in undisturbed Cambrian strata, that would serve as excellent evidence of a fundamental flaw in Darwin's theory. If you could find a natural specie such as Kirk Cameron's crocaduck, evolution could not explain such a chimera, and forces at odds with Darwin's theory would obviously be at play.