JMO... but I had a HIGH reving BB years ago... the springs
on the shaft will never control the side movement...
the adjuster is off center so the push rod is pushing
on a angle moving the rocker over... if that action is
fast enough it will develop a larger lash... if the
PR pops off of the adjuster it tends to drop in close
to the shaft... all you need is a single gouge in
the rocker to create the stress area and break(since
the PR is still working the rocker BUT at a MUCH higher
rocker rate)... the alum spacers control the side
loading(a hard shim they sell on both sides of the
spacer will reduce wear)
The burnt oil is a AFTER FACT... the PR dented the rocker
and increased the friction on the shaft.... if the other
rockers dont have the burnt oil look you would know
its a after fact