It's all where your sitting, imagine you park under a tree and see a guy 3,000 yards away in an open field. When you fire your below the tree line so your round goes out and finds its target. When that same guy returns fire the arc of his round is going fall into the impenetrable trees. It's all about creeping forward or back till you get that magic angle. Gv's are finicky, there fun but can be pretty frustrating.
And those guys that don't have good graphic cards are prolly more frustrated by hitting an "Invisible tree" than you are by getting shot through one once in a while. I had bad graphics before the update and I hit invisible barns, trees, barney, who knows what it was but it sucked.
The moral of the story is it's an inconsistent game and you gotta roll with the punches