I fully agree.What I am also seeing here is why defining the problem is so important in a problem solving process. A wrong perception or definition can throw one far away from the actual or root cause.
The key word is *should*. I remember one scenario where rusted parts showed up in the customer's assembly line. There was a lot of in-house investigation and it took a couple months before we got the customer let us send observers to their assembly plant. All the time they had been screaming at us, it was their own receiving and storage method which was the cause.This problem is being made far too complicated! Rust occurs through inadequate protection or inadequate storage. Determine where in the process the rust was detected then work upstream looking at where the process went wrong. Is the protection adequate at each stage? Is the storage area and packaging suitable? Is there good stock rotation?
The causes and countermeasures should be apparent!
I went through a couple of similar situations working with a company that was supplying parts for the V-Rod some years back. Until we got in and watched their processes. Our team several times ended up showing Harley where their own internal processes were at fault.