We have two conflicting tales: that the Jedi killed their parents, and Mae caused the fire. My guess is that there is truth laced in both sides; neither being completely right. Master Sol is clearly feeling guilty about something, though. That itself doesn't mean that the Jedi went to a planet, went to a village, and pulled an Anakin in the Jedi Temple during Operation Knightfall. It could mean that he feels guilty over an intended good faith interaction going bad, and there being some deadly consequences that came out of it. Perhaps the witch coven Mae and Osha came from antagonized the Jedi, threatened some Innocents, and Master Sol believes the Jedi could have handled it a different way
Until we see the story play out I think it would be inappropriate to make any damning, absolute assumptions about the nature of what happened. That's my own perspective, anyway.
Also that small monologue given by the sith mask guy at the end of ep1 was awesome
Palpatine managed to destroy the Jedi not through sheer, brutal force, but through manipulation behind the scenes--turning the public against them, turning the Jedi against the ideals they were meant to stand for. I think that is what the mask guy is saying, and it does feel to me that this is essentially an early version of that mindset Palpatine took up and perfected later on.