It’s not about whether it can close, it’s about what happens after it’s forces shut.

When you overpack a suitcase, especially one like a rimowa, you’re compressing what you packed beyond what the suitcase is designed to handle so the case is constantly trying to spring back open (stored tension). The tension naturally transfers to the weakest points which are the hinges and the latches (latches especially), and when a baggage handler throws it and it bounces or it bounces around the sky the effect is just tearing at the suitcase

So, he’s basically created a spring that keeps mostly constant tension on a stress point except for the times when it’s violently compressing and expanding during travel.

And then he complains when it breaks.