The incomplete records of the Hillary Clinton email investigation released by the FBI raise questions about the conduct not only of Clinton but of her top aides and the staffers working under their direction. Perhaps the most serious is whether the Clinton team destroyed evidence which they were under legal order to save and produce to congressional investigators.

Out of a massive investigation, the FBI has released just two documents: a heavily-redacted version of its summary report and a writeup — the so-called 302 — from agents' July 2 interview with Clinton. The rest, including reports from interviews with other players, remains secret, although the FBI has shared it with Congress, with redactions and under tight viewing restrictions.

Shortly after the two documents were released on the Friday afternoon before Labor Day, Rep. Trey Gowdy, chairman of the House Select Committee on Benghazi, sent out a statement suggesting he does not believe the documents tell the full story, and that if the full story were told it might suggest wrongdoing on the part of the Clinton team.

"The FBI selectively releasing Secretary Clinton's interview summary is of little benefit to the public unless and until all relevant documents and witness interview summaries are released," Gowdy said. "The public is entitled to all relative information, including the testimony of the witnesses at Platte River Networks, the entity which maintained the private server. The public will find the timeline and witness responses and failures to respond instructive."

What did Gowdy mean? What are the still-unreleased documents? And what does "instructive" mean? Here is what we know, from what the FBI has released, plus earlier reports about the investigation into the September 11, 2012 terrorist attack in Benghazi:

Nine days after the attack, on Sept. 20, 2012, the House Subcommittee on National Security, Homeland Defense, and Foreign Operations, which is part of the larger Committee on Oversight and Government Reform, sent a document request to Clinton, who was still Secretary of State. It was a broad request, intended to cover anything written or recorded in any way that might have something to do with Benghazi. It without question covered emails. The State Department produced some material in response, but never any emails from Clinton.

Several months later, on Aug. 1, 2013, the Oversight Committee issued a subpoena covering the documents asked for, but not received, after the Sept. 20, 2012 request.

In May, 2014, the House Select Committee on Benghazi was formed. On July 23, 2014, the State Department agreed to produce records to the committee. The FBI report picks up the story from there:

[The State Department] sent a formal request to former Secretaries of State on October 28, 2014, asking them to produce e-mails related to their government work. After State requested that Clinton provide her e-mails, Clinton asked her attorneys, David Kendall and [Cheryl] Mills, to oversee the process of providing Clinton's work-related emails to State. Heather Samuelson, an attorney working with Mills, undertook a review to identify work-related e-mails, while Kendall and Mills oversaw the process. Ultimately, on December 5, 2014, Williams & Connolly [Kendall's firm] provided approximately 55,000 pages of e-mails to State in response to State's request for Clinton to produce all e-mail in her possession that constituted a federal record from her tenure as Secretary of State. State ultimately reviewed the 55,000 pages of e-mail to meet its production obligations related to [Freedom of Information Act] lawsuits and requests….Clinton told the FBI she directed her legal team to provide any work-related or arguably work-related emails to State; however she did not participate in the development of the specific process to be used or in discussions of the locations of where her e-mails might exist. Clinton was not consulted on specific e-mails in order to determine if they were work-related.

In December 2014 — after the emails were sent to the State Department — Mills ordered people whose identity was not revealed by the FBI to delete Clinton email archives from their computers. Also in December 2014, according to what Mills told the FBI, "Clinton decided she no longer needed access to any of her e-mails older than 60 days." Mills then ordered an unidentified tech staffer to "modify the e-mail retention policy on Clinton's clintonemail.com e-mail account to reflect this change."

So that was it: the Clinton team produced what it said were all her work-related emails to the State Department and then ordered its tech people to destroy everything, and then put a new policy in place in which no emails would be saved for more than 60 days.

Then everything changed.

On March 2, 2015, the New York Times reported the existence of the secret Clinton email system. The next day, Gowdy's Benghazi Committee sent a letter to Kendall's law firm "requesting the preservation and production of all documents and media" relating to Clinton's emails. The day after that, March 4, the full Benghazi Committee issued a subpoena ordering Clinton to "produce all records in unredacted form" on the following:

For the time period of January 1, 2011 through December 31, 2012, any and all documents and communications in your possession, and/or sent from or received by the email addresses hdr22@clintonemail.com"> hdr22@clintonemail.com, hrod17@clintonemail.com,"> hrod17@clintonemail.com, or any other email address or communications device used by you or another on your behalf, referring or relating to:

(a) Libya (including but not limited to Benghazi and Tripoli);

(b) weapons located or found in, imported or brought into, and/or exported or removed from Libya;

(c) the attacks on U.S. facilities in Benghazi, Libya on September 11, 2012 and September 12, 2012, or;

(d) statements pertaining to the attacks on U.S. facilities in Benghazi, Libya on September 11, 2012 or September 12, 2012.

Remember that at that time the Benghazi Committee had not received a single Clinton email related to Benghazi.

Shortly after the New York Times report, according to the FBI, Mills asked Platte River Networks, the company that was handling the Clinton server, to do an inventory of what was on the servers. (Mills had, of course, ordered the old emails destroyed and a new retention policy put in place back in December 2014.) On March 25, 2014, the Platte River Networks people took part in a conference call with Bill Clinton's staff. At that point, an intense round of deleting began.

Sometime between March 25 and March 31, according to the FBI, a tech worker not identified in the report had what he called an "oh shit" moment. He realized that he had not done what Mills had ordered back in December 2014. In his first interview with the FBI, on Feb. 18, 2016, the unidentified staffer "indicated that he did not recall conducting deletions based upon this realization." But then, in a follow-up interview on May 3, 2016, the staffer "indicated he believed he had an 'oh shit' moment and sometime between March 25-31, 2015 deleted the Clinton archive mailbox." The staffer used the now-notorious BleachBit to do the work, and manually deleted a backup as well.

But the story is a little more complicated than that. The FBI found that on March 9, 2015, Mills sent the Platte River Networks staff, including the unidentified worker, an email, in the words of the FBI, "referencing the preservation request from the Committee on Benghazi." In his first interview with the FBI, the staffer told agents that "he did not recall seeing the preservation request referenced in the March 9, 2015 e-mail." But then, in the May 3 follow-up interview, the staffer "indicated that, at the time he made the deletions in March 2015, he was aware of the existence of the preservation request and the fact that it meant he should not disturb Clinton's e-mail date on the [Platte River Networks] server." The staffer also told the FBI he did not consult any colleagues, company legal counsel or anyone else "regarding the meaning of the preservation request."

According to the FBI, the Platte River Networks staff had a conference call with Kendall and Mills on March 31. By then, the deleting was done. What did they talk about? The FBI report says Platte River's attorney advised the staffer "not to comment on the conversation with Kendall based upon the assertion of attorney-client privilege."

Mills told the FBI she knew nothing about the deletions the staffer made in March 2015. Clinton also said she knew nothing.

So what does the story mean? Does it mean an incompetent, or rogue, staffer deleted the emails on his own even though they were under subpoena — and then initially lied about it to the FBI? Or was there something else at work?

That's where Gowdy's somewhat vague statement comes in. "The public is entitled to all relative information, including the testimony of the witnesses at Platte River Networks, the entity which maintained the private server," Gowdy said. "The public will find the timeline and witness responses and failures to respond instructive."

Not to put words in Gowdy's mouth — he was unavailable for comment this weekend, aides said — but the chairman appeared to suggest there was more to the story than appeared in the two documents released Friday by the FBI. Gowdy, who has said he has seen all the investigative documents the FBI sent Congress, hinted that the Platte River Networks witnesses told the FBI more than is in the incomplete documents now available to the public. What those witnesses said, and what they refused to say, along with a more complete timeline of events, would be "instructive," Gowdy said.

But even with the fragments now public — the Clinton 302, the overview report, but none of the many other witness interviews — it seems fair to conclude that staff on the Clinton team destroyed material that was under subpoena. Whether that was unwitting, or whether it was something else, is not known, at least publicly.

There's no doubt that Clinton intended to destroy her email archives after choosing which ones to send to the State Department. That's what Mills' December 2014 directive was apparently intended to do. Given that the Benghazi investigation was well under way and there had been multiple document requests and production agreements, the effect of Mills' directive, had it been carried out at the time she sent it, would have been to destroy the evidence that had not been handed over to the State Department before anyone knew to ask for it. But apparently the Platte River Networks staffer's carelessness led to the emails not being destroyed in December 2014, remaining in existence until March 2015, when their existence was publicly disclosed and another subpoena issued for them. Then they were destroyed.

It's clear Clinton did not turn over all her work-related emails to the State Department on Dec. 5, 2014, as she claimed on many occasions. The FBI said it recovered "17,448 unique work-related and personal e-mails" that Clinton had not turned over. Of those, at least 30 were said to contain references to Benghazi and thus would have been responsive to the various congressional requests and subpoenas going back to Sept. 20, 2012.

Of course congressional investigators will want to know more about what happened. And of course Republicans will press the issue as the presidential election approaches. But there's a simpler reason for the FBI to release more information: After all the investigating, and all the talking, the public still doesn't know what happened.