President Trump’s lawyers do not know just how much the White House counsel, Donald F. McGahn II, told the special counsel’s investigators during months of interviews, a lapse that has contributed to a growing recognition that an early strategy of full cooperation with the inquiry was a potentially damaging mistake.
The president’s lawyers said on Sunday that they were confident that Mr. McGahn had said nothing injurious to the president during the 30 hours of interviews. But Mr. McGahn’s lawyer has offered only a limited accounting of what Mr. McGahn told the investigators, according to two people close to the president.
That has prompted concern among Mr. Trump’s advisers that Mr. McGahn’s statements could help serve as a key component for a damning report by the special counsel, Robert S. Mueller III, which the Justice Department could send to Congress, according to two people familiar with the discussions.
Mr. Trump’s lawyers realized on Saturday that they had not been provided a full accounting after The New York Times published an article describing Mr. McGahn’s extensive cooperation with Mr. Mueller’s office. After Mr. McGahn was initially interviewed by the special counsel’s office in November, Mr. Trump’s lawyers never asked for a complete description of what Mr. McGahn had said, according to a person close to the president.
Mr. McGahn’s lawyer, William A. Burck, gave the president’s lawyers a short overview of the interview but few details, and he did not inform them of what Mr. McGahn said in subsequent interactions with the investigators, according to a person close to Mr. Trump. Mr. McGahn and Mr. Burck feared that Mr. Trump was setting up Mr. McGahn to take the blame for any possible wrongdoing, so they embraced the opening to cooperate fully with Mr. Mueller in an effort to demonstrate that Mr. McGahn had done nothing wrong.
On Sunday, Mr. Trump’s lead lawyer dealing with the special counsel, Rudolph W. Giuliani, appeared to acknowledge that he had only a partial understanding of what Mr. McGahn had revealed. Mr. Giuliani said his knowledge was secondhand, given to him by a former Trump lawyer, John Dowd, who was one of the primary forces behind the initial strategy of full cooperation.
“I’ll use his words rather than mine, that McGahn was a strong witness for the president, so I don’t need to know much more about that,” Mr. Giuliani said of Mr. Dowd on NBC’s “Meet the Press.”
But Mr. McGahn, who as White House counsel is not the president’s personal lawyer, has repeatedly made clear to the president that his role is as a protector of the presidency, not of Mr. Trump personally.
Legal experts and former White House counsels said the president’s lawyers had been careless in not asking Mr. McGahn what he had planned to tell Mr. Mueller’s prosecutors. The experts said Mr. Trump’s lawyers had the right to know the full extent of what Mr. McGahn was going to say.
Robert F. Bauer, a White House counsel under President Barack Obama, said Mr. McGahn’s lawyer may have taken the most prudent course for his client by not addressing “each and every detail about the questions that were specifically asked and the specific answers given.”