Why everybody believes that centaur wanted to kill Harry ? It rather seems like centaur was disarming him. And it is even possible, he was under imperius curse (from Quirrel) while disarming Harry. He seemed to be surprised about what he was doing (looked up with widened eyes) and he apologised.
I believe Quirrel just wanted to interrupt the conversation between Harry and Centaur.
Why everybody believes that centaur wanted to kill Harry ? It rather seems like centaur was disarming him. And it is even possible, he was under imperius curse (from Quirrel) while disarming Harry. He seemed to be surprised about what he was doing (looked up with widened eyes) and he apologised. I believe Quirrel just wanted to interrupt the conversation between Harry and Centaur.