Not bullshit: i also am dutch and my driving instructor taught me this right hand and look over shoulder technique. But i agree with parent comment otherwise: our solution to being "Doored" is more about common sense using the mirror (its there for a reason) and looking around, and not what hand we use. Its a helpful aid maybe. After reading this on HN i noticed i do tend to use BOTH hands.. left on the big grip and right on the handle-button. I think using both hands here is important as this is what allows you to retract the door, as other comments pointed out.