Anyhow, getting to the point, there used to be this website that had mpeg clips of every network and news channel covering that day. You could watch the entire replay for that day, and then clips of coverage for at least the week after. In any case, back in '02 I watched the alphabet network coverage & the 24 hour news channel coverage over and over. I remember the initial coverage of the Pentagon much as you describe.
One thing I would stress however is that things were very chaotic that day, to state the obvious, and it's not odd if the initial reports were erratic just as initial reports often are. By example, just earlier this week they initially reported that 50 houses slid off that cliff in Laguna, CA and it turned out to be a dozen or so.
Whatever the case, I should go to hell for posting this, but you might find this site interesting: Pentagon Strike.
I've seen that one before....it makes a pretty strong argument for an alternative theory to the "official"story.
I just find it amazing that there were people who knew it was going to happen and nothing was done.
I did find the site you posted interesting and it did raise some questions in my mind.
So I went to the Popular Mechanics site and reviewed the information there to get a complete perspective.
I think that if you do the same you will see that PM is much more convincing in their presentation of the facts.