Exiting left from I-40 West at exit 70, the driver moved into the left turn only lane without a signal, and then, after pulling forward and stopping for a moment, cut abruptly back into the thru-traffic lane, with no turn signal, causing me to nearly rear-end him, and the car behind me to swerve into the other lane. He was either talking or texting on his phone before during and after this, and when I gestured that he should hang up, he waved it mockingly in his rearview mirror.