95% sure he was part of that little troll brigade based on the fact they all registered at roughly the same time, interacted with each other the most, and mass voted site-wide.

While it's not possible to know who votes on what, I can see how many votes an account casts in total (comment votes and submission votes). Seeing a new thread get posted, and it have an immediate multiple vote score while refreshing the member list to see 3 new members all cast an additional vote somewhere on the site makes it possible to determine the likelihood that they're just voting on each other's stuff.

I'm also fairly certain who is behind these little brigades but don't care enough to get involved in childish games. I'll just quickly clean up their mess and continue on with my day, no big deal.