Stay to left side of the divide,make sure you are far enough forward away from the little drop off I kept dying from same thing, and then my buddy pointed out what I'm going to tell you. That rocket has a MASSIVE splash damage. I thought I was safe by that little rock, but if he shoots while you behind the rock..the rockets hit the face of that little drop off I mentioned above, and the splash damage from that will kill you. If you stand out in the open in the middle of that area, and about 5-10 ft ahead of that little rock, the splash won't hit you and you can jump over the rockets. Once he told me that's what was happening, the only times I day now is when I forget that the splash can get me - lmao I still go to the little rock to reload or regenerate my shield.