On Friday, Elon Musk appeared on the witness stand in federal court in San Francisco, testifying in a trial brought by Tesla investors. They say Musk's tweets in 2018 may have crashed the stock price of Tesla, leaving shareholders holding the bag. Musk told the jury, "Just because I tweet something does not mean people believe it …" Correspondent John Blackstone has the story. Air Date: Jan 21, 2023