I haven't seen the suit, but I would imagine (as a lawyer) that the defendant's filed an affirmative defense akin to assumption of the risk. Under this legal theory, a Plaintiff may be to blame for a percentage of the damages. For example, let's say that a jury (if a jury trial) believes that the damages are $100,000, but that the Plaintiff, the injured hunter, should have known the risk of hunting a wild lion and thus was 80% at fault. Based on these numbers, he would only recover $20,000.00.
Still, the problem would be that the company would be found liable, and I can almost promise you that hundreds of suits would follow and, ultimately, put Federal, or any other ammo maker, out of business.
I can understand the hunter being upset about what happened, but he should be upset at himself - and maybe his PH. A PH should check his client's guns and ammo and, more importantly, the applicability of the ammo to the game being hunted. Unfortunately, the injured client, as they always do, go after "deep pockets" - meaning Federal Cartrdidge Co. because it has (much) more money than the poor PH.
Zachary