Correction:Lawyer here - Not a mistake at all. She would be liable as an accessory, under aiding and abetting. The exact crime varies between common law jurisdictions, but she is laughing along when Michelle is speeding and terrorizing the other driver. In common law jurisdictions, that would be viewed as encouragement of Michelle's committing a crime (she explicitly says she didn't tell Michelle to stop), which is a form of abetting, and indeed carries criminal charges.
Correction: Lawyer here - Not a mistake at all. She would be liable as an accessory, under aiding and abetting. The exact crime varies between common law jurisdictions, but she is laughing along when Michelle is speeding and terrorizing the other driver. In common law jurisdictions, that would be viewed as encouragement of Michelle's committing a crime (she explicitly says she didn't tell Michelle to stop), which is a form of abetting, and indeed carries criminal charges.
swordfish