Opinions please

Are you saying that the distributor is not rotating at all? I am just following this thread to learn.
Oh no... it can still rotate and Spark, see it can even rotate somewhat less than engine speed at cranking because in such a scenario the chain driven by the crank just slipped and re settled on the cam gear setting the cam timing out enough not to run.

A lot of times they only finally slip in 2 ways "most of the time"... and that's under hard acceleration and more under deceleration, inertia takes over at a point when the chain and gear is just too loose and worn.

Hope that sheds some light.