A recent EE Times story, blog and related comments have focused on the reasons for the DOJ's exclusion of any cover-up by Toyota of electronics-related SUA defects. People are spectulating that it was a golden handshake deal.
But maybe the standard of evidence required by state court for imposition of punitive damages, as in Bookout, was lower than in a criminal prosecution. I remember that plaintiffs attorneys Jere Beasley or Cole Portis mentioned the standard of evidence in either their opening or closing arguments, and one of them said the standard was lower in that case than in a criminal case--a "preponderance of the evidence" (51% or more) was required, in contrast to "beyond a reasonable doubt" (98% or more?) in a criminal case. I also remember reading that a federal court requires a higher level of evidence than a state court. The DOJ is obviously operating by federal and not by state standards.
*******************************************************************************
Wikipedia - Beyond reasonable doubt is the standard of evidence required to validate a criminal conviction in most adversarial legal systems.
Generally the prosecution bears the burden of proof and is required to prove their version of events to this standard. This means that the proposition being presented by the prosecution must be proven to the extent that there could be no "reasonable doubt" in the mind of a "reasonable person" that the defendant is guilty. There can still be a doubt, but only to the extent that it would not affect a reasonable person's belief regarding whether or not the defendant is guilty.
If doubt does affect a "reasonable person's" belief that the defendant is guilty, the jury is not satisfied beyond "reasonable doubt". The precise meaning of words such as "reasonable" and "doubt" are usually defined within jurisprudence of the applicable country.