When you read the headlines through the lens of the actual law, finding "scant evidence" and "evidence" are exactly the same. The FBI has found evidence of intent to break classification rules.
Now, how can that be? Doesn't every criminal statute require proof that the defendant intended to break the law? No, some laws, like those related to negligence do not require proof of intentional lawbreaking or that actual harm be done. A common example is operating under the influence of alcohol. The mere fact that a policeman finds one behind the wheel with a blood alcohol level over a certain percentage is enough to convict. Parts of the Espionage Act are like that. Even though they involve negligence rather than intent to commit a crime, they are still felonies. She is not off the hook.
Add that to the fact the State Department and the Intelligence Community IGs have already found more than 2,000 items of classified information found on her server, 104 of which she sent herself, and 22 found to be information that was Top Secret.
The Felony statute at at Sec. 793 enumerates six separate crimes. The first three, (a)-(c), require the prosecution to show intent to violate the law and to cause harm to the national security. However, two, subsection (e) and (f) apply merely on the basis of mishandling classified materials without actual intent to or the effect of exposing secrets or to violate the law. The standard articulated in (e) is even lower, requiring merely that the defendant acted knowing that unauthorized release "could" cause harm to the national security. That is a much lower standard of proof than proving someone intended to such harm.