10 second count-Louisiana Test Question I Missed

[Popey]

True of False:

A1 is dribbling the ball in front court when B1 knocks the dribble away and the ball goes into backcout, rolling all the way into the free throw lane in backcourt. Ruling: The official waits until A1 has control of the ball in backcourt in the lane before beginning the 10-second count.

I answered True and got it wrong... I am confussed. Since the ball obtained front court status, wouldn't you have to have player control again in backcourt to start a count, or is team control all is needed at this point to start count? When would you start the count?