In just the same way you can get away from taxes by lying vehemently... he lost his job and reputation in less than three years.
Since the paper itself was okay, but the data was falsified, obviously it was hard to prove the data was false until other studies not only showed it, but also his reputation was discredited and (presumably) investigations finished.
Incorrect data can happen even to a good paper in good faith due to instrument error.
The paper in question, again, was lots of "maybes" and no direct conclusions. The earth shattering conclusions were reached in press conferences where the guy lied vehemently, and the journalists ate it up like coke.