Half-deserved. He warned you to leave, but could have passworded the server, which coulda made him look like an admin. He told you to get off the field many times, as you said, making it seem like you didn't even though you were told to many loving times, making a kick at most deserved.
However, as you also said, he left the server, and the supposed spam and ban happened after he left, and the "again proceeds to ban me" implies you were already kicked/banned. Anything you wanna tell us?