SO I WATCHED IT...
And yes, it was lame. I've organized flops myself, in the past, so I won't attack the attempt.
In principle, I agree with actions to (non-violently) appropriate live television time in an effort to break the monopoly of media opinion on 9/11, albeit for a few seconds.
Such actions can be effective. This one was not:
1) Bad timing: They didn't choose the right moment (several mentions of Al-Qaeda came and went without triggering them). The least of their failings.
2) Incoherence: At the start, they yelled comments relating to the panelists (addressing Matthews). These were totally incomprehensible. Big mistake. This is not the right place for complete sentences, or for doing anything other than a tight script. The whole action in fact was almost entirely incomprehensible. (What is "Building 7"? Those are the only words that came through on TV, and this rather late in the action, and they mean nothing. You have to at least say "WTC.") It took Maher himself, after the incident, to actually explain what the protest was about. Otherwise no one watching who wasn't already a 9/11 head, or who didn't read the sign in the quarter-second it was flashed, would have understood anything.
3) Too slow and hesitant: In a crowd like Maher's - who are totally mob-like in their applauding his every comment - you don't want this to last very long. Serial outbursts were a mistake. These allowed Maher to harness his crowd.
4) In short, it didn't look like they rehearsed or planned very well. They came off like idiots, and Maher totally dominated.
In my opinion, the right way:
All of the protesters should have stood at once, immediately gathered together at the bottom of the audience area if possible, linked arms and chanted in unison the same thing over and over, something very simple. In keeping with their message, something like: "What about WTC 7? Bill Maher - Stop the 9/11 Cover-up!" They would have had about 30 seconds to make it coherent. They should have ignored anything Maher said and allowed it to wrap quickly (i.e., go out easily after 30 seconds), because extending it only gives him the advantage, and trying to yell as you are pushed out always make you look like a lunatic.