Right now it is another gimmick round. Manufacturer will make sure advertisement is only going to show what they want. The real test will be on the street. Then and only then will we know if it is a viable cartridge.
As to the legal aspect of the round. Hard to tell. It will depend on the DA or in a civil case the plaintiffs lawyer. I'm sure they will paint the person using it as blood thirsty with a desire to kill.