Hashirama was dead at his feet as far as he knew. What'd you expect? He was looking down at the 'dead body' of his greatest rival. WWouldn't you be smiling? He wasn't cocky. He was outsmarted and flanked( while looking at the 'dead' body) when he thought he finally beat hashirama.Yeah,let's forget that Madara is a cocky man,and had the same cool atitude before he got stabbed by Hashirama.Yeah,let's.