"I must get the name of that luggage manufacturer."
I want the name of the ammunition manufacturer, so I can buy a different brand.
With respect to pulling the trigger to "reset the firing mechanism", that is borderline absurd in my opinion. Yes there are a few firearms where it is required to pull the trigger to accomplish this-or-that, but this is bad design and somewhat rare. If your weapon isn't equipped with a decocker, just leave it as it is. I mean you unloaded it and made sure of that, right? Pulling the trigger afterwards serves no purpose except to cause problems.
I agree that trying to unload while concealed was the primary cause. Sometimes it's hard enough to verify the chamber is really empty even in good lighting conditions. If your extractor slips off the round and you get too lazy to look down in there, bad deal. Hard to give everything a good look inside a suitcase.