I watched him since your first ban-poll on him for over 5 rounds.
He played all normal despite teamkilling you one time, what either was on purpose, due to his higher ping, or his playskill.
Still you stated another ban-poll the next map for no reason; since he did fine afterwards. Due to your previous bans, you got punished for pollabuse.
I didn't saw him teamhitting/teamkilling like a maniac, but he appeared to a complete newbie to the game (mod), so I blame his skill. If he fucked you up before, take screens and provide them to admins, not necessary in a whole ban-request, PM's also work.