I see this is a ploy to gain strength. The one who walks away gains power. This trick has been used for eons. It tells the other person I am the boss and I am in control.
It also PO the other person who feels embarrassed. You better have fire power to back up this move. In relationships, when one person walks away it often leaves the other person begging or PO. Many men beat up their partners when the partners either give them the silent treatment or walk away from a tense situation.
Trump probably felt Kim was planning to pull the plug, so he acted first. In this case, Trump comes across as the one who left Kim at the altar. Fortunately, even if he is PO he does not have the fire power to act out.