You CAN shoot between the trees, if you find the right angle, and a little luck... In fairness, I have killed quite a few GV's that way, even tho I couldn't see them...
If this is true, I wonder if it might have something to do with the new terrains, and being compatible with older machines... Thats the only thing I could think of, that would cause a fallback to the old gamey tricks again..
RC