There is indeed something to the media manipulation scenario. It would not be the first time, by far, that I have seen the media selectively film scenes and even "stage" things to serve some agenda (often just higher ratings). However, the Independent Media Centre, (an original source of the rumor) which is so far out to the left that it is close to developing a red shift, has an axe to grind here too.

The most glaring example of media "editing" in my experience was the 1989 Bay Area earthquake. The media filmed a few blocks that had been seriously damaged, and when broadcasting, made it look to the casual observer like all of San Francisco was destroyed. In most of this area, there was no visible damage at all (I had some things fall off of shelves). My relatives were frantically calling, sure that I was doomed.

I saw a photo on the Internet which I unfortunately can no longer locate. It showed one single Palestinian dancing with an anti-American sign, and nearly surrounded by about thirty cameramen all filming him.