When I first looked at the pictures, I thought that the rear of the bed was somehow higher than it should be, and the dynamic weight of the camper concentrating on that one spot had led to the crack. But when I look closer at the first pic with the camper installed, it looks like the eyebolt is pulling that corner of the bed up. Even if you aren't overtightening, if the area where the bolts is mounted isn't strong enough, the camper could start to pull at that corner over time and vibration. I could also see that happening if you hit a really big pothole or rut, the kind that kind that gives you a headache.
We've had our Hawk in two trucks, a 1/2 ton and a 3/4 ton and gone over some pretty rough forest roads and 10s of thousands of highway miles and have had no issues like that. We always have had either a stall mat or a purpose built rubber bed mat under the camper, but that wouldn't help if the eyebolt mounting area is weak.