The picture below is from the leaking fitting found in OTS BP5160019 Y62 Rear.
The middle O-Ring (red circle) had two knicks in it which were 120° apart from each other just like our 3x 5.5mm cross drilled holes.
The arrow is pointing to mark that is actually in the surface, as though a drill burr was there during zinc plating, then possibly knocked off during assembly with the middle O-ring fitted.
Seeing this hose has two banjo fitting on it, I removed the other fitting to look for simular marks in either the O-Rings or the fitting, there was neither.
If you could please check stock of VD70010003 and let us know if you have any ideas or discoveries.