A coworker of mine got tired of the fact a couple of people in my office (a guy and a woman validating him) were unable to play along with others.

These two weren't bad people out of the box but couldn't handle the idea that others may not agree with them or simply be different or have different values. This was not a problem in itself, except for the fact that these two reacted by trying to create groups inside the workplace and attempted to isolate and classify as "bad" those that wouldn't suck up to them.

This was high-school kind of behavior taken to the workplace. And the fact that neither of the two liked the job made things worse because the only thing they could change to make their lives "easier" was the social aspect of the office... I'm talking about the guy saying "yeah, boss A is deaf and doesn't get it while boss B is a useless, dumb and should be ignored". This kind of crap was said just to pull himself up in front of everyone while he acted nice and piss on other coworkers when the bosses were around just to impress them...

A coworker of mine got tired of this, and while he kept his head down and acted really passive towards these two, he actively turned the tables on them by presenting evidence to our bosses of their behavior, of their comments and attitude towards people and company owners, and about how they acted behind those with authority.

His actions were so decisive that these two got shut down and almost fired. Now they act isolated, offended and want nothing to do with the rest of the group.

My coworker says he acted like this because he can't just go into the office willing to punch poeple and if he forces himself to behave then the others have no right going around acting like assholes.

He basically pretended people to behave in the office and given those acting like assholes were popular and two of the oldest employees, he couldn't stand them doing this and back stabbed them big time in order to stop them. His reasoning is that if they decided to stop playing by the rules by saying whatever was on their mind no matter what just because they felt "superior", then he had an excuse to stop playing by the rules and mess with them involving the company owners.

Is this sort of action bad? Is manipulating and acting in a shady way like this justifiable if the aim is to cut the toxic coworkers out?