Ship/Fleet Exp

[General Hawkwing]

No, I wasn't using CSM's, I was using PPB's. I realize you don't get exp. for damaging only destroying.
My question is: could not destroying the first ship in the 1st combat, prevented the fleet from gaining exp. in next combat.
After the 1st combat, my fleet slaughtered about a dozen ships in 3 combats and still had exp. 0%. I then disbanded the fleet, recreated it with the same ships and after the next combat they gained exp. equal to the ships killed.