Letting a car go in front in the situation above: you're probably causing an accident.
I disagree. In this situation, you are letting the left turning car move to the middle lane of this five lane road. From there, they can make a better decision of when to go. You aren’t causing an accident by letting them go TO THE MIDDLE LANE. From that point on, it is their ability to merge that may cause an accident. But they are supposed to stop in the middle lane and check that they can merge BEFORE they merge.