UNfoirtunately, I think he also doesn't give a shit whether he himself succeeds or not. I cannot imagine he'll actually be able to kill Canute, which means he'll probably die. And he's probably gonna be all like "oh well, Valhalla, here I come" and not even lose his smile over dying.
Thorfinn fleeing is ... ugh.
Although I have to say: It looked like NONE of Canute's soldiers was killed in that clash, that's just ridiculous. At least some random arrows should have hit someone on their side.