If there is found to be a consistent level of the same problem with the lot of ammo you bought I would say there might be grounds for legal action.
This is one of many reasons that when I buy ammo to carry in my self defense guns, I buy enough to load all the magazines I will carry and have several rounds left over. This way, there is ammo left to test in case of any type of legal action in a post shooting situation.
If you have to shoot in defense of your life, the Bad Guys lawyer (or his surviving family members if you killed him) may sue you for wrongful death or some other BS charge. (if you live in a state with no civil liability protection law) It would be helpful to have rounds of the ammo you used in the shooting, same box, same brand, same lot everything, to show that you didn't alter the ammo or otherwise change anything with it before the shooting.
Always cover your butt.....it's the only one you have.