He probably was banned from a server, not global banned.
Tell him to try to connect again to the server he was temp banned from later, he should get in.
Also, if he was just temp banned from one server, he should be able to connect to the other servers. He isn't banned from every server, is he?
Jitspoe has nothing to do with server temp bans, you have to talk with the server admin who did that.
