Of course he cannot tell the truth, it is too damning, and he knows it. In the unlikely event of got that far, his only recourse, in front of a grand jury, would be talking the fifth. Not that it will ever get that far. And, would Cult45 be bovvered by him taking the fifth? He could serve up Mueller, or Sessions, or Rosenstein's noodle on a platter to Ainsley Earhardt, starkers, with a carrot up his bum, and they would cheer him on.
'Week 64: Trump’s Not Afraid of Lying to Mueller. Just Telling the Truth.
His attorneys claim the special counsel is laying a 'perjury trap,' but telling untruths has never bothered the president as much as revealing actual facts.'
'Writing recently in the Washington Post, legal scholar Stephen Bates noted that while Mueller probably has the legal and constitutional authority to subpoena the president, it would be dumb to do so. “The president says no. Mueller goes to court. The judge orders Trump to comply. He still refuses. The judge, treating him like any other defiant witness, holds him in contempt of court. Then what?” Bates writes. Mueller can’t very well use contempt charges to throw Trump in jail if he resists. “Up against an irresponsible president, a responsible prosecutor will pick his battles,” Bates concludes: A subpoena death-match is not the hill Mueller wants to die on.'
www.politico.com/magazine/story/2018/08/11/trump-mueller-interview-perjury-truth-219350