As much as I like Block B, they were in the wrong in this instance. The intentions behind their behaviour need not be debated as either way it has caused due offence. Nickhun was not rude or nasty, but rather diplomatic and the same goes for the other 2pm members. You would do Block B better by showing your respect to 2pm and not be so rude, rather than exacerbate a situation.
This is why kpop annoys me, so much fan-drama.