I think part of Wikipedia is defining what a term means, many words are used in many different ways. I remember 'ethnic group' being a pretty vague term before Wikipedia was around. Everyone uses the word 'evolution' in a different way. I don't believe in 'correct' definitions so much as consistent and useful ones. I propose we adopt the following: 
Evolution: Umbrella term, any change over time, as stated in first sentence of article. 
Natural selection, horizontal gene transfer, etc...  Mechanisms which explain evolution, the observation. 
Theories of evolution: A theory to explain one particular facet of evolution in terms of natural history (e.g. Out of Africa Theory, Cretaceous–Paleogene extinction event)
The other problem with this article is that many scientists were motivated by a desire to explain why livings things are adapted to their environment or to explain the diversity of life. As opposed to Evolution per se
The Precambrian rabbit wouldn't falsify Evolution so much as discredit all of our current theories about Evolution. What do we think?