Sarcastic Behavior

Hi,

I was playing a chess game on the internet. After my opponent made a blunder, he requested to take back the previous move. I declined by capturing his unprotected piece. Then, he started to play like suicidal chess i.e. to throw away all his pieces until he was checkmated. In this situation, is it correct to say he is being sarcastic? If not, what is the best word to describe his behavior?

Thank you in advance.