In journalism, there's a time-worn saying: It's not the crime but the coverup that gets them every time.

A look at the federal indictment outlining the alleged crimes of House speaker-turned-lobbyist Dennis Hastert (R-Ill.) when he was a high school teacher and wrestling coach indicates that in his case it was actually a combination of the two.

As has been widely reported, federal prosecutors charged Hastert with two federal crimes last week. Technically, he was charged with lying to federal investigators and making cash withdrawals from his accounts in increments designed not to draw the attention of federal authorities. As many more Americans probably now know this week than did last week, banks are required to report cash transactions of $10,000 or more to federal authorities. Federal officials then scrutinize these transactions on the grounds that they may be linked to criminal or even terrorist activity.

In the days since the indictment went public, so, too, have reports about the underlying "wrongdoing" that Hastert wanted so desperately to conceal. Both the Los Angeles Times and the New York Times have reported that Hastert allegedly paid a person described in his indictment as "Individual A" nearly $2 million to keep private Hastert's alleged sexual abuse of a former male student. Several other reports have speculated -- and there is still a fair bit of speculation in much of what has been published about the matter -- that the statute of limitations for these alleged crimes has expired, meaning it's too late to prosecute Hastert in criminal court.

And that's where the lesson of the Hastert debacle -- if we want to call it that -- begins.

Hastert’s indictment makes no mention of any pending federal blackmail or extortion charges against Individual A, or charges against Hastert for any type of sex crime.

So, had Hastert removed money from the bank to pay Individual A, then told federal investigators the true reason for those withdrawals, he probably wouldn't face any criminal charges. It's also possible that the American public wouldn't know a thing about the alleged turmoil in Hastert's personal life.

The FBI, as a matter of policy, does not confirm or deny the existence of an investigation. The agency reveals information gained during an investigation only if that investigation leads to a prosecution. Of course, FBI investigations and information uncovered during them have certainly been known to leak to reporters -- particularly with someone as high profile as Hastert.

Given that policy, if Hastert had told the FBI the truth, agents probably would have investigated his story. If they found that the statute of limitations -- the time window during which a crime can be prosecuted -- for Hastert's alleged behavior had expired, Hastert probably would have been free to do as he saw fit with his money.

As Jennifer Rodgers, the executive director of Columbia University's Center for the Advancement of Public Integrity, told me: "It may come as a shock to people, but it's not inherently illegal to pay hush money. What you can't do is lie to the FBI."

So public officials, public and semi-public figures, that is the the takeaway.

Requesting payment or other items of value in exchange for silence, even receiving the proceeds​ of extortion, is generally illegal. However, paying someone who has incriminating or even embarrassing information, well, isn't.