To be fair, he has been dealing with his self-inflicted Twitter challenges. The day Hillary was exonerated, Trump and his campaign were discussing Iraq instead of coordinating a unified message on Hillary, the Lynch meeting, and the Obama-Clinton corruption axis.
That was a wonderful opportunity and it was squandered because of the total lack of message control - and timing as another poster points out above.
The Greeks had the perfect term for this aspect of rhetoric - especially political - Kairos.
You must have missed the speech he gave that very night that was over an hour long and was covered in its entirety by CNN and partially by Fox and MSNBC. He attacked Hillary brutally over the email scandal throughout the speech (and even added in mentions of Whitewater and her cattle futures scandal).
By the way, the Iraq issue was the press’s choice for a diversion. Trump had said the *exact* same thing about Saddam Hussein before on many occasions. The media simply chose to start a bunch of BS about it this time for obvious reasons. They were grasping at straws with hopes of helping Hillary. Why didn’t they make a big deal about it the first half dozen times he said it?