I would venture that a real grenade body (whether inert or live) will show up on the xray well enough to define the shape and determine "holy crap thats a grenade". However, you add in the clutter and electronics and other stuff, and it becomes a situation where you may not be able to determine if it is rigged to something, or just a paperweight. I am willing to bet money that the item stayed right there in the xray until the EOD guys pulled it out - which is exactly what should have happened if there was any question at all. Even if they were able to determine whether the item is not surrounded by anything that causes questions, I still do not wish to see the TSOs handling something that could be live (even though a grenade will not explode without outside involvement - much like a firearm). You and I know from previous experience, that grenade is not going to do anything until you activate it, the same with a firearm - not everyone has had that experience or training. While I understand that it is a remote possibility that anything bad would happen, I still want the TSSEs or EOD guys to handle grenades or possible explosives. With all the modifications being done to items all over the world, I would hesitate to handle one nowadays, because there may be something changed or modified that I might miss. This was not something picked up out of the shipping container on the grenade range, this was something they have no idea of the lineage on, caution and calling in someone with focused experience and training is an easy call.