Again this is part of that pendulum swing. In an effort to combat low reimbursement rates the government agreed to faster bill payment which in turn lowered timeframes for quality/fraud control and the result is huge payments on faudulent bills before the fraud is identified.
While the government did not pay out over a billion dollars, they likely paid out $250 to $500 million before suspending payments. Little of the money will be recouped and few will see any substantial jail time.