I was thinking more along the lines of distribution damage. There are many hands the comic passes through before it hits the shelf. I find myself often upset at my local comic shop when there are spine creases or blunted corners on new comics because of the employees poor "handling" of the comic when taking them out of the distributor boxes. They might even put the stack on the counter top where the book on the bottom gets smeared with some stuff that was not cleaned off in time.
The best way you can argue printing defects is to find other copies with similar problems.