Title 13 Chapter 54 does not prohibit "hollow point" rounds. It requires dealers to record the sales of "hollow nose" rounds, however. But, they do no appear to be prohibited.
As for the firearm, all that appears to be required is a "permit" that allows one to purchase a firearm as well as a firearm identification card. It could be that he HAD those items, and that it was a permit to possess and/or purchase a handgun.
It may also be that any offenses alleged were misdemeanors or NJ's equivalent low level offense, and did not require bail prior to release on a signed promise to appear. Some states (like mine) make possession of a loaded and concealed handgun a citable offense ... (just don't get caught with a concealed knife out here! Whooo boy!)
If you really want to know what's up, call the police department that arrested him. or, call the jail that held and then released him - see what they can tell you. No one here can give you a certain answer because no one here knows the circumstances or the specific crime(s) alleged.
- Carl