If it looks like raw bone then chances are he is rubbing the top of his cage to hard and scraping off his skin to the bone. I have seen chameleons do it before.
it's not a shed. yea he is shedding right now but he's had those sticking out for a few weeks. i haven't seen him rub against his cage though and he isn't able to touch the top where the light is
It's more likely that the burned skin has died and what you're seeing is the skin that has split and it just looks like bone. But if a burn is bad enough it can remove all the skin over a bone.
we're actually trying to find him a new home. so if anyone in the western washington area is interested, we're asking 100 for him, his cage, and the mist king