I don't understand your consignment manager's comment. First by breaking open the slab at this point, you are destroying the evidence. Second, the inner well has nothing to do with the tampering. In this case. the outer well and only the outer well was compromised, allowing the culprit to swap out the inner well or the label. The opening of a slab has been discussed on the Boards before. If done carefully, the only evidence you would see is probably that hairline crack you mentioned. The location, inch from the corner is where it pops.
Should the consignment manager be charged with a crime?