Trump's biggest mistake here?

Not coming ashore on Puerto Rico with the first wave of assistance, arriving sooner than most thought he would; surprise them all; see the damage, talk with the victims, encourage aid workers and meet with the Puerto Rico officials...and the mayor. Oh, and wave to the cameras. 

Then, in those now "Infamous" words, it would have been "a good-news story."  And when he met the Mayor, he might have said, "Got issues?  Got ideas?  Call me direct" and given the mayor his White House number, with a shrewd order to his minions to immediately "put her through."  "Shewd" because people under duress, in extreme stress, want to vent. She'd be free to do so--and he would allow her the opportunity...privately. Say little...and listen. THEN tweet on his close connection with the Mayor. 

But no.  Not on the agenda.  Nor anyone else's that we can determine.

The man gets what he deserves--an opportunity to predictably prove himself a pontificating bully again.