Lawful New York Gun Owners Acting Recklessly

Local news reports

Rome Police announce that two men have been arrested following an accidental shooting at a business that came dangerously close to hitting a customer.  According to authorities, 56-year-old Ricky J. Hoke and 45-year-old Edward F. Lemmon Jr. are now facing reckless endangerment charges.
While at Hoke's business, Hoke Auto Sales on Erie Boulevard, he was showing Lemmon a recently purchased handgun around 9:30 a.m.  Hoke handed Lemmon the weapon, who pointed the gun at the office wall and pulled the trigger, authorities describe.
Law enforcement officials say the bullet passed through the wall into the parking lot, passing through the sleeve and stomach area of a customer's coat. The male customer was not injured.
Rome Police Detective Commander Timothy Bates said the men removed the magazine from the gun but were unaware of a bullet in a chamber.  The weapon, which was determined to have been possessed legally, has been secured by police.

First of all, this story goes against all the nonsense we've heard about New York being a de facto gun free zone. Only celebrities and politicians, we're continually told, can own guns legally. Obviously this is not the case.
Secondly, this story goes against the idea that gun owners are, for the most part, responsible and intelligent enough to safely manage their weapons.  In fact, the propaganda goes, we're all better off because of them.  Obviously that's just not the case either.
One thing I will say about New York is this, as opposed to, say, Indiana or Florida, one mistake like this and you can probably forget about owning guns again in the future.  At least I hope that's the case.
Can someone please explain how it's possible for a gun owner to remove the magazine and not consider the fact that there might be a round in the chamber?  We read about this quite frequently as the explanation for an unintentional discharges.  But, I still don't get it.  Are these people that stupid?
What's your opinion?  Please leave a comment.