Someone tweeting a picture isn't exactly verification. There's no real way to tell if that picture has anything to do with the location or bus in question.
I'd really like to see some more verification - especially after the way the last Google Bus "incident" turned out. (A guy who at first appeared to be an employee trying to shout down the protesters... was actually a guy there to support the protesters, and make an artificial 'scene')
Edit: The SF Chronicle is currently reaching out to the witnesses to get a better feel for the story. I'd expect something to come out in the mainstream news real soon.
I'll be waiting for it. If I knew Craig Frost, I might be more willing... the stilted writing style of the original just leaves me wanting to see more viewpoints.
I'd really like to see some more verification - especially after the way the last Google Bus "incident" turned out. (A guy who at first appeared to be an employee trying to shout down the protesters... was actually a guy there to support the protesters, and make an artificial 'scene')