Unless I'm mistaken, it seems that you're incorrect on your interpretation of that particular law. Unless, perhaps, you steal the pen from a government employee.

http://codes.lp.findlaw.com/uscode/18/I/31/641

I wonder if everyone realizes that it wasn't Google that designed the packaging, but likely they just designed the artwork on the outside.

As for the box itself, it seems that a packaging engineer just got their fit between the two halves a little too tight... it's not like they put it in heat-welded clamshell packaging!