My thoughts as it was happening this morning, when I heard that it 'was a drill'.

First, emergency broadcasts need to be approved before initiated, so if it was an error, someone's head is going to roll.

My other thought though, is what if someone was able to hack into the detection system and make it appear that there actually was a missile launched, which triggered the response...We certainly would not be told this.

The implications would mean that the one who hacked in could possibly remove actual incoming missiles from the detection system. Ponder that for a moment...