Car drivers not looking for bikes is a factor and was taken into account in the research. The problem is the sheer number of “Sorry mate I didn’t see you” incidents implies there is something more going on than just careless drivers.
Research outside the field of motorcycle accidents has shown that an object heading straight towards you is difficult for our eyes/brain to pick out. Our brains are wired to identify moving objects. If something is heading directly towards you then there is limited movement to identify and you simply blend into the background. It is not until the car driver pulls out that you move across his horizontal vision, the brain suddenly registers this closing object, they freeze and hit the brakes.
I am all for hi-viz clothing and own a luminous yellow, dorky looking jacket. But swirly patterns, even brightly colored ones, can act as camouflage. The main factor to effective camouflage is not color matching to the background but breaking up your outline. If you can paint a swirly pattern on a battleship and have it blend into the blue ocean, what chance do we have riding down main street with neon signs behind us.
The point of all this is that you can wear all the hi-viz clothing you want, there will be times when the driver will not see you. You need to ride expecting the car to pull out if you want to avoid becoming a statistic.
USS Leviathan WW1