That's what the Blacks Law dictionary says.
I don't care that Black's Law Dictionary equates the two. They're not equivalent, and the difference between them goes further than merely a matter of degree.
As for the situation... The individual who lost his gun to a couch was careless. Whether CC or OC, I'm often checking possession, usually by checking mere weight. Failure to maintain positive (that's the checking part) of one's firearm is careless.
The FBI agent who did a back flip, losing control of his firearm, which then discharged, was reckless. It wasn't because he did a back flip while wearing a firearm. It's because he
knowingly did a back flip with a holster that was incapable of retaining his firearm during a back flip.
So why isn't the couch potato guy reckless? Because he had no
knowledge that his actions of sitting in the couch would risk losing his firearm. This could have been due to lack of experience or lack of training/education. Therefore, he was merely careless.
And what about the parents? Were they careless or reckless? If they
knew that letting their child run wild in IKEA ran the risk of that child finding and discharging a firearm, then they would be reckless. But how could anyone know that? That meets no reasonable test as it's an extremely rare event. Ergo, at worst, they were merely careless in letting their child get out of their sight and/or immediate control. It may be child neglect, if it's found they failed to provide adequate supervision, but what's "adequate" for IKEA? For the child's age? Those smarter than I on that subject would have to investigate.