First we parked a jeep behind the 38's and fired one round each time to establish a base (and basic knowledge) of the areas you can shoot and have this happen. Then we flew 38's at slow level flight (just above stall speed) and fired at it using ANY single mounted gun we could find, (Yak exc. 303, .50, 20mm firing only one gun at a time trying to make sure shots were accurate of course)
I would be more than happy to re-test with you if you doubt me. I don't want look foolish if i'm wrong. But i have seen in game, and as stated, in testing. That for me personally I have had it happen to me as stated.