Don't all ground targets work this way? I'm virtually positive that the other day when I dropped on a VH, but missed by just enough to leave it up, and the guy behind me strafed it the rest of the way down with his 50s and he must have gotten the credit for taking it out (I didn't, I'm pretty sure).
Not complaining, just stating that as far as I know that the way it is for all non player target objects, so it's really not that inconsistent.