I hate it when my coins come with a surface anomaly that cannot be directly attributed to a known inherent variable of the minting process, package and shipping process, handling process or other natural or unnatural methods of interface with the surface. What will the grandkids say if grandpa can’t positively identify the mechanism(s) responsible for the unfavorable, unsightly condition?
He only asked for opinions. I Love the site all the time, but I don't have to like you all the time... BE NICE!
To repeat: What caused the mark is not important; but an accurate description of it is. A pin or knife can make a scratch, A mark done with the chopping motion of a hatchet is a different kind of mark. Children tend to keep things simple. PMD is simple and as children, they are not expected to know or care to go further. None of this should matter to a child or anyone not deeply involved with coins.