Do you have the replay of this battle available?
There are various conditions that each class uses to signify that it is active. One of the conditions for CVs is having at least 1 point of damage dealt to an enemy ship by planes.
I'm wondering if there's an over-riding condition that a DD has at least some direct damage or spotting damage as a minimum. Since no damage occurred at all, that may have been an issue as neither condition could have been fulfilled.