Who?
Okay, mistakes were made. WotC dun goofed when they has notorious trolls and asshats Zak S and the RPG Pundit involved in testing the game. That was a failure of researching people and doing background checks. But after the community pointed out they were asshats, WotC didn't work with them again.
Foolish, but no one was "hurt". (And better than a lot of companies who worked and hired those people long afterward.)
There's the rumour that Mearls shared emails including senders with Zak. But that was never proven. I've never seen any evidence of that. Not a single screenshot.
It's not so much a rumour as a conspiracy theory.
It was suspected because Zak brigaded some of the people who spoke out. But since these were already people ZS and the Pundit had fought with previously there's a simpler answer: they just made educated guesses as to who complained and targeted past victims.
We can't hold Mearls responsible for their actions. The only person he hurt was the person he insulted by name in the Google+ post. And he apologized to them personally.
Anything else is just the community asking him to jump through a hoop and dance for them. A show of contrition and public humiliation until we deem he has sufficiently been "punished".
