I disagree completely. Say the butterfly doesn't get eaten and stays alive for a few days longer. During those few days it might land on a tree near someone, and that person might stop to remark upon it for 5 seconds. These 5 seconds spent remarking upon it means they leave the forest 5 seconds later. This 5 second delay means they have to stop at a red light on the way home that they woudn't otherwise have had to stop at. This means they will come across an entirely seperate group of cars on the journey home. Due to this they might have a collision they otherwise wouldn't have had, and their offspring will never be born. This offspring may have grown up to be the next President, and thus the course of human history would have been permanently altered because the butterfly didn't die at that moment.