Methinks the game just recognized that any attack where you're within viewing range points you out like a sore thumb. Probably a limitation of both the hardware and the engine--I mean, it probably wouldn't be easy to recognize that firing off a round from the back of a jeep is different than one fired from the side of a tank. 
Who knows.
'course, I always run around in an APC with a rocket launcher on the back, so I don't run into those problems.
Who knows.
'course, I always run around in an APC with a rocket launcher on the back, so I don't run into those problems.