Hostile to whom and on what basis?

If two companies decide to merge, is it by default a hostile action? I don't think so. And what if later anti-monopoly agency decides that it was an infraction and blocks the merger? Then I think it was.

Does informing voters about something is a hostile action by default? I don't think so. But if it was later decided that there was a law breach, then it would be hostile action.

All people and even megacorps are innocent until proven guilty. Maybe even until accused of being guilty by some authority, though it is pushing it. But until someone at least does something to show their displeasure and point fingers, then yeah, no hostile action has happened, it was fair play.

So to answer your question - vote bribing is 100% a failure of the organizer of said vote and of the law enforcement system (in bigger cases) IF that organizer or govt never complained about it or did jack shit in general. But if they at least complained or better did something about the problem, then yes, vote bribing failure would be a shared responsibility of both bad actor doing it and the people who hadn't done any reasonable prevention in advance.

Since it is obvious that assigning equal weights to the countries can and did lead to the vote manipulation, I can say that ISO committee had NOT done reasonable prevention of vote manipulation and so is also guilty, just as bad actor MS.