There are problem when they honk or flash light from behind . You don't do the lane change immediately with that intidimation because there may be possibility of accident with the car in your right lane . Move to the right lane when it is safe to do so. Don't bother what the guy is doing from behind. It happended with me few times in Doha . Sometime they are so arrogant that they will not change the lane and go past you . My dear friend,don't get upset . Do defensive driving and save yourself ! If you want to stay in the Middle East you have to live up with it . I involved with many such incidents with local national in many ME countries , but I had never won against them . Law will go in favour of Local national.