BRENDAN SMIALOWSKI/AFP/Getty Images

Is Trump lying about why he fired Comey, or did he simply forget?

The mainstream media has been having an extended debate about when it is appropriate to label President Donald Trump a liar. While Trump undeniably tells many falsehoods, there is good reason to be cautious given we can’t know Trump’s subjective state. What could be a lie might also just be delusion or ignorance.

Trump’s latest tweet provides a good example of the dilemma:

This directly contradicts what Trump told Lester Holt in an interview last May on NBC News:

Last May, The New York Times reported that the day after Comey lost his job, Trump told the Russian ambassador, “I just fired the head of the F.B.I. He was crazy, a real nut job. I faced great pressure because of Russia. That’s taken off.”

Trump’s tweet thus contradicts both is earlier statement and reporting. But is it fair to say he’s a liar? Perhaps he’s merely forgetful?