Vicious Hammer glitch/exploit?

Is it really a glitch though if that's what the creators intended, regardless of how fair it seems to us?

I suppose one of the many things I do not like about Nexon is that they'll screw up, not say anything about it (so everyone thinks it's business as usual), then they come back to correct their mistake with widespread bannings of people thinking it was ok to do. They need to react faster.