I think approving the eruv de-legitimizes a rav, and I would not rely on him for anything.
(And if you name names, I’ll keep on de-legitimizing, so don’t try me.)
And I don’t know if it is muttar to be mazik to prevent chillul shabbos, but if it is, I would personally vandalize it. (And I wouldn’t even spray paint pictures. Hey, do you think it’s the same people?)