After some lunch and shopping, figured I had enough charge to get home, but silly me I just unplugged the car - and a minute later I had an email and an SMS message from ChargePoint:
"The station at which your vehicle is charging, PORTER SQUARE / SHOPPING CENTER, has detected that the plug has been removed from the vehicle, and therefore your vehicle is no longer charging. Please physically inspect the vehicle, the charging station, and restart the charging session if necessary. You can avoid this notification in the future by using your ChargePass card to end the session, before unplugging the connector from the vehicle. "

Very cool!