The way Science is set up makes it very difficult for this to happen.
When a discovery, especially an important one is made the world tends to hold it's breath for independant corroberation.
There are a number of examples where deliberate falsification has been discovered, there was a Guy in Germany and another in Korea.
http://www.sciencemag.org/cgi/content/summary/ 277/5328/894
http://www.medicalnewstoday.com/articles/99298 .php
Then there are numerous cases of self-deception where Scientists have jumped to early and wrong conclusions - cold fusion being the most famous of these.
So generally these things tend to come out because of the highly competetive nature of Science and there are rather obvious smoking guns - most often, remarkable results nobody else can reproduce.
Finding God would not be the end of Science anyway - after all the most obvious problem with all Gods is you have to ask where they came from.
The answer is always an unscientific - "Go away it's a mystery we can't understand"
It seems many people find it acceptable that a God we can't understand created a universe, but unacceptable that a Universe came into being in a way we can't understand all on it's own.
Guess it's because Universes aren't people shaped but Gods are!