I am sure you are right but why would anyone feel the need to carry a gun in to a Disney park? What if it was pulled out and fell into the wrong hands and someone was shot? I hate guns!! I hate that they fall into the wrong hands to easy. I really feel for every single police officer on the streets because they are always in danger of some nut case with a gun.
So ... for your scenario ... you'd have to have the following happen:
1. Person A brings in their permitted, concealed weapon.
2. Person A's holster somehow fails, and the gun falls out.
3. Person B just happens to walk by as this occurs.
4. Person B decides, just then, that he should pick up the gun and shoot people.
A more likely scenario would be:
1. Person B gets a gun illegally.
2. Person B comes in and shoots people.
But because of Person A's concealed weapon, you could have
3. Person A shoots Person B.
Just FYI, countries that have strict gun control laws, such as England, have no long term drop in violent crime. If someone wants a gun, they will get it, no matter what. Same as committing a crime, or anything else.
No reason to hate guns, they are just a tool. Thats like hating a dryer because its exhaust can get clogged and burn down your house. Instead, hate the people that commit crimes with guns.
But its just the way. No personal responsibility and legislate everything.
People that have their weapons legally are not the ones you hear about committing violent crimes. So taking those guns away wouldn't stop anything.