Team ban would have no effect on it at all. The only thing a team ban does is remove your edit, delete, and post buttons for that team. If you still have the post box there, a team ban will NOT prevent you from posting. In other words, team bans are easy to get around, and wouldn't have much affect on you.
Based on what he's saying, it has to be a problem with his browser. The only thing SC wise that would do this is a post limit for the first week, or a post time limit to prevent you from putting more than 1 post in a particular thread until more than 30 seconds have past since your previous one.