Well, I get your points, but there's no way it is an intended mechanic for turret.
Also you did not address this: It turned for last two shots even though the omen was visible the whole time. What is that about? Did he went out of the range exactly after the first shot so it turned straight? Even if the answer is yes, then it still would make much more sense for it to shoot to the same direction even if it cant turn that much behind it. If you do a quick peek around the corner and bait a turret shot it still shoots to the same corner you went behind without reseting its possition to 0 degrees for remaining shots.