Hitting the Keys too Hard - MicroKorg

[Ace Slowman]

Ok first of all Im sure this is a overly paranoid question.

The other day a friend of mine was playing on my microkorg and when I walked out of the room, I heard the CLACK CLACK CLACK of him slamming on the keys. Of my brand new Microkorg. Should I be the slightest bit concerned about this? It sounds fine, absolutely nothing is different from before, but it set off some dormant OCD apparently . He is definitely not touching that synth any time soon haha. What would it take to damage a keyboard?

Thanks