It is true that getting doored is not part of the Dutch vocabulary as it is not something that happens often. But there are more reasons than grabbing the handle with the opposite hand.
A non extensive list: 1) Dutch car drivers all have been bicyclist before they get their driver license, everyday to school more than an hour being nothing being frowned on. 2) Major transit bike routes have separate bike lanes, the tiny narrow ones of the gif in the article barely exist. 3) Bike lanes in cities usually are placed between the footpath and the parked cars, with most of the times a 50cm wide band left of the bike path allowing for car doors being opened without going over the bike paths, usually this is used for planting trees too 4) All politicians drive bike, the Dutch Prime Minister comes to work on his bike 5) There are local associations part of the national http://fietersbond.nl in every town and they passionately lobby every time they see an opportunity. 6) these volunteers are highly respected and their input is valued by the municipalities 7) one of the prime goals of Dutch national ministerie of Traffic is lowering the number of injured and death in traffic, good recording of cause by police is step one, good statistics then determine the ways roads are laid out. 8) On smaller roads without a separate bicycle path, as a bicyclist you're always on the watch if someone might step out of a car and try to keep a distance by bicycling towards the middle of the road which isn't an issue as this is low traffic street, major bike transit always has separated bike paths with distance to the parked cars. 9) during driving lessons, watching bicyclist is a prime part of the lessons and a good driver keeps an eye on the mirrors for back-coming bicyclist and will warn passengers on the back seats before they get out.
And there are probably more reasons that Dutch have few accidents being doored.
A non extensive list: 1) Dutch car drivers all have been bicyclist before they get their driver license, everyday to school more than an hour being nothing being frowned on. 2) Major transit bike routes have separate bike lanes, the tiny narrow ones of the gif in the article barely exist. 3) Bike lanes in cities usually are placed between the footpath and the parked cars, with most of the times a 50cm wide band left of the bike path allowing for car doors being opened without going over the bike paths, usually this is used for planting trees too 4) All politicians drive bike, the Dutch Prime Minister comes to work on his bike 5) There are local associations part of the national http://fietersbond.nl in every town and they passionately lobby every time they see an opportunity. 6) these volunteers are highly respected and their input is valued by the municipalities 7) one of the prime goals of Dutch national ministerie of Traffic is lowering the number of injured and death in traffic, good recording of cause by police is step one, good statistics then determine the ways roads are laid out. 8) On smaller roads without a separate bicycle path, as a bicyclist you're always on the watch if someone might step out of a car and try to keep a distance by bicycling towards the middle of the road which isn't an issue as this is low traffic street, major bike transit always has separated bike paths with distance to the parked cars. 9) during driving lessons, watching bicyclist is a prime part of the lessons and a good driver keeps an eye on the mirrors for back-coming bicyclist and will warn passengers on the back seats before they get out.
And there are probably more reasons that Dutch have few accidents being doored.