My entourage of six pigs and I killed the Tree Guardian/Optimus Pine. I had a Torch equipped and used it as a weapon. The Guardian died and left a small fire that burned briefly. Then, instead of crows flying into and out of the screen, I saw flames, although they moved and sounded like crows. I then chopped down a nearby tree which dropped Charcoal for the first time I've ever seen it. When I picked it up, a dialog box titled "An error has occurred" popped with this message: "Error: Module Crashed: NaCl module crashed." When I attempted to reproduce the bug, everything proceeded as it should have. The crows were normal. The tree that had formerly dropped Charcoal had withered and did not drop Charcoal. I hope this is helpful.