Donald Trump has repeatedly questioned whether Clinton is physically fit to be president. Asked about the incident, the Republican nominee said only: "I don't know anything about it." Trump left the ceremony after Clinton.
I agree that Trump handled it well. Best to wait and see what the DNC does / does not do over the next few days. Trump can continue to say what he’s said for some time now, that Hillary lacks the integrity and the stamina to be POTUS.