Tesla Model X owner driving with an open Falcon Wing door hits a passenger bus (teslaoracle.com)

So why didn't the driver close the 'falcon wing' door in the first place?

There are at least 3 different alerts that appear in the displays of the Model X when the car's motors are engaged and the falcon wing is extended. In addition, a distinctive audible alert occurs with the door open. To drive with the falcon wing extended indicates a willfulness on the part of the driver.