It is definitely odd, and having dealt with numerous firearms cases, having sold firearms and cases, I would be upset if told the solution was drilling an additional hole in a case. There are any number of things that could have gone wrong with drilling through the case, including the case shattering or pieces breaking off, both of which would render the case no longer secure. The employee could've missed with the drill and put a drill bit into the stock or onto the metal of the firearm. The additional hole could weaken the structure of the case, resulting in it not adequately protecting the firearm from damage from drops, etc.