This is an odd issue you are having. Without having the device disassembled in front of me it is very difficult to fully diagnose. However from your description I can hazard a guess that some part in the phone is grounding where it shouldn't. In other words, a protective film, cable casing, or PCB layer has been compromised or is missing and is shorting to another component or frame of the phone. With modern devices voltage/amperage being so closely monitored a short can cause kernel panics or random shutdowns depending on the severity and location of the short.
My recommendation is to verify that there are no differences between the two frames when looking at the black insulating layers. Damage to these layers could be the cause.