There is little doubt that special counsel Robert Mueller is a man of the law. A few weeks ago, in a brief public statement, he expressed his hope that he not be requested to testify further about the Russia investigation. In short, he noted that his carefully prepared final report speaks for itself. But with a subpoena authorized and likely to be served, Mueller made the choice that Americans have come to expect from him: undiminished respect for government process.

His initial choice was the correct one under Department of Justice (DOJ) practice. However, a "perfect storm" of unfortunate, even if well intended, departures from departmental policy would collide with Russian malefactors to cast electoral doubt upon the actions of almost everyone. The misstep of missteps began with former FBI Director James Comey's pre-election public exoneration of Hillary Clinton for her use of a private email server.

As it would turn out, this unusual and unorthodox exoneration later would be partially rescinded by the discovery of possible additional evidence. Then in the maelstrom of political objection that should have been anticipated, the peculiar exoneration was reinstated, yet again, at the 11th hour of the campaign. Comey's gratuitous comments about why Mrs. Clinton did not violate the law, but also why he was choosing not to prosecute, introduced politics into law enforcement - and we are the worst for it.

In mid-July, Mueller will be examined by congressional committees. We can anticipate that he will stay very close to the text of his report, which is commendable since the application of law often requires nuance that can be expressed only in writing. And since Mueller is cleaning up the mess created by Comey and many others, some of them still under other investigation, he must not allow himself to be pushed to commit Comey's error anew. If Mueller does attempt to elaborate, this serious moment begets serious questions:

If it was your intent to be bound by longstanding Department of Justice Office of Legal Counsel (OLC) policy concluding that a sitting president cannot be indicted, what did you see as the purpose of your investigation? Recognizing that it is not your role as special counsel to opine on the correctness of an OLC constitutional judgment, do you believe as a senior member of the law enforcement community that the OLC determination is correct? You have stated that it would be unfair to indict President Trump because he would be accused but then not given a timely opportunity to clear his name. Is this still your understanding of the nature and purpose of the policy? Does a determination that a president in office cannot be indicted place the president above the law? Why or why not? Do you believe that a sitting president under indictment could perform Article II responsibilities? Would not an indicted president be devoting disproportionate time to his personal defense and also be subject to domestic and international manipulation? Assuming the correctness of OLC opinions, doesn't this then place a disproportionate burden upon the Congress? Would it not be preferable to indict a sitting president, and even convict of lesser criminal offenses, than to immediately go to the constitutional process of impeachment? Which approach - indicting or impeaching - is more consistent with democracy? Well over 1,000 former prosecutors and DOJ lawyers have concluded that were Trump not the president, the facts would support a criminal indictment. Is it correct that your report does not necessarily disagree, since you make a point of writing that the investigation does not exonerate him? If a president leaves office by impeachment or resignation, or is displaced by the collective action of the vice president, cabinet, or other congressionally specified entity, could he then be indicted and subjected to criminal prosecution? If a president is impeached by the House, but not convicted by the Senate, he continues to serve until the conclusion of his electoral term, as did Bill Clinton. When President Clinton left office he was not criminally prosecuted. Constitutionally, could he have been, or would this have placed him in "double jeopardy"? The Constitution provides that the president and all civil officers of the United States shall be removed from office on impeachment for, and conviction of, treason, bribery or other high crimes and misdemeanors. Treason and bribery are extremely serious offenses. Do you share the legal assumption that the basis for impeachment does not require proof of a formal crime? In other words, is the meaning of "high crime and misdemeanor" a matter for interpretation by Congress that neither the president nor the Supreme Court could second-guess? Your report concluded that the facts did not support a conspiracy between Russia and candidate Trump to disrupt the 2016 election. Similarly, you conclude there was an absence of coordination with respect to an unlawful objective. Your report, nevertheless, contains numerous documented interactions between Trump's campaign and Russian nationals you indicted (in essence for stealing Democratic National Committee emails). These interactions are commonly referred to as "collusion," which is not a crime per se. Did you interpret your investigative mandate to be strictly limited to the determination of whether a crime had been committed? With respect to whether the president or his campaign obstructed or attempted to obstruct your investigation, you left the matter undecided by referring to the DOJ policy against indicting a sitting president. But even if the OLC opinion is correct, is it not an overly narrow interpretation of your responsibility not to give Congress the benefit of your prosecutorial judgment as to whether the president could have been tried for obstruction were he not in office? In transmitting the report to the attorney general, were you effectively inviting him to reach a substantive conclusion on the meaning of obstruction, which you carefully avoided making yourself? Putting to one side your understanding of the law and the nature of the facts, can you outline what you believe to be the appropriate relationship between the White House, the attorney general and the Department of Justice in interpreting and applying the law in a case where it is likely that the president's personal interests are at issue?

These are tough questions and, as every litigator knows, in some cases it can be wiser not to ask.

Douglas Kmiec served as the U.S. ambassador to Malta from 2009 to 2011 and headed the Justice Department's Office of Legal Counsel (OLC) under Presidents Ronald Reagan and George H.W. Bush. He is the emeritus Caruso Family Chair in Human Rights at Pepperdine University School of Law, and founding editor of the Notre Dame Journal of Law, Ethics & Public Policy. Follow him on Twitter @dougkmiec.