What struck me about your observations is that Twitter in this case mirrored very closely how information spreads in the physical world via word of mouth around disasters.

Having lived through the Sept 11th attacks on the World Trade Center in New York City and run from the clouds of ash & debris as the South Tower collapsed, I can tell you first hand that the rumors, exaggerations and scamming were very similar. There were reports that there were 11-13 hijacked airplanes, rumors of additional targets in New York City and elsewhere and price gouging for basic services in the immediate viscinity of the World Trade Center. There were also countless amateur photographers and videographers capturing the unfolding disaster. Many of the photos were ultimately compiled into a digital (and hard copy) archive: http://hereisnewyork.org/gallery/book.asp

I’ve read similar accounts from the sarin gas attacks on the Tokyo subway (http://bit.ly/aegWfy).

In some ways, it’s good to know that Twitter reflects our real & very human reactions in difficult times. But as you point out, it’s important to remember the challenges that these sorts of real-time man-on-the-street reports present in tracking breaking stories that are also quite emotional.

It would be interesting to know how soon after the intial reports the accurate story of that day’s events emerged on Twitter, as the broader community worked to correct the misinformation.