"Lin Feng you have shown me so much of the impossible"
He saw him kill a guy crawling on the ground from injuries and beat a demon beast by hitting its weak point. Thats all.
Is there a whole mess of dialogue and fights going on in the Light novel that we are missing because the characters in this story are all acting weird. You got all the jerks in the series mocking and promising death to the MC while they are actively losing a fight badly.
so he created a feud by unnecessarily killing an arsehole and as the result his friends suffer, and no, the Mc doesn't reflect on that, only thinks that he should have been better at kicking ass. Typical.