The President lacks consistency in many areas, but one aspect in which he is guaranteed to be utterly on point is being thin skinned and taking offence and going off in a huff.
He lacks dignity in many areas, one of them is remembering his on the world stage, and he needs to have the respect of his office, and everyone else's.
The mark of a statesman would be to ignore something not meant for his ears, and carry on with the dignity that goes with his rank.
Sadly, the President and the concept of dignity are non-existent bedfellows