Helicopter PVE Rocky Canyon bug

The attacking forces of D2 has a bug. One of the enemy’s 106 mm AT gun (AI) will spawn inside the river. We tried using both 9K127 and Hellfire B ATGM against it but cannot kill the target. The 30mm guns cannot do it as well.
This make the completing of this task impossible. Please re-arrange the place of that specific bot, making it touchable for the players.