I believe this is by design. You were in CS mode, just not burning gas. Being in CS mode results in various changes to how the car thinks and is prepared to supply power, as we all know there are plenty of times in CS mode where we are regenning or the gas engine is otherwise not running. It correctly noted you did not burn gas, so your mileage numbers will not be effected but I am sure you were technically in "CS" mode.
Originally Posted by Rusty
I dream of a better world, where chickens can cross the road without having their motives questioned