I agree that this is super fishy! It seems like it may be someone inside of the News channel that did something to make the alarm go off. Too much of a coincidence.
I highly doubt the "button" to start this alarm is that easy to "accidentally push"... yeah, it was done on purpose.

I'm nut sure I agree with the phone thing though. Many phones like that have multiple lines and you have to press a certain button to call out or to switch lines. There is no need for a "special phone" for that call. That's movie stuff. I'm sure they get more than just missile calls from that phone, and they probably have multiple phones attached to the same lines.