I have also been trying to work out the oiling path and I think that the mechanism for the oiling is, that as the pistons fly apart on the up stroke, the suction tries to evacuate the timing cover by lifting the sprung loaded ball off its seat and the partial vacuum in the timing case sucks oil into the spindles of the rockers and timing wheels via the holes into the crankcase. So, far from dumping oil on the road, it actually sucks it back into the crank case of the engine.
On the down stroke of the the pistons, the ball closes and more oil is forced into the spindle holes, so they get lubricated twice on each cycle of the engine.
Regards
Tim