You made a major error at the fourth word of your question. Proof is something left to mathematicians. It is impossible in science to prove anything. That always takes people sometime to accept because that is what they think scientists spend their time doing, i.e. proving things.
Science works with evidence and what it accepts is based on the preponderance of the evidence. However, sometimes certain facts are so strongly evidenced that scientists generally accept they are all but proven. For example, the evidence shows that in our solar system the Earth orbits the Sun. Technically, a scientist must remain sceptical and open to the possibility that one day this model of the solar system will be disproven. However, no rational scientist really expects this to happen. There are other areas of science that are generally considered to be all but proven in the same way such as the atomic theory of matter, the germ theory of disease, gravity AND evolution.
The information about the star that is so far away is not evidence, at all, of evolution. Where I think you are confusing things is that one of the arguments of many opponents of evolution is that there has not been enough time for evolution to occur. All this star can do is demonstrate that the universe must be old enough for evolution to be a possibility. However, there are stars in the universe that existed before the Earth did and so whilst a star may show the age of the universe it does not show the age of the Earth. There is, of course, a very large body of evidence that not only supports evolution but that shows the Earth is old enough to have provided the time for evolution to occur.