Fighters shot down by Tac Bombers still on the ground

I had a fighter unit patrolling over an enemy province w/airbase when I found a group of 2 Tac Bombers sitting on the ground. When I decided to attack them, my fighter was eliminated! WTH?! There was also a anti-tank unit in the province but with an AA defense of 1.0 I would have only expected them to damage my fighter. Therefore, I am assuming that the bombers on the ground with their 3.0 AA value did the majority of the damage.

Aircraft on the ground should have a combat rating of 0.0 for attack and defense against all units, including aircraft.

DrewGator