I thought the same, but as soon as I landed in my helicopter to check out the damage to the tank (which was targeted as white) the tanks started firing at me and killed me.....
Therefore there was somebody inside that Tank!
I have a few Triggers that send a message as soon as somebody leaves the tank.
(count crew myEnemyTank != 3)
to detect if somebody left the tank, but sometimes I get the white target before they even start getting out of the tank!!
Weird!