I just checked again, server is streaming (Data Last Received time was updated).
Thanks for the PBSS, I'm looking into it.
Edit : My bad, I wasn't looking at the right server, somehow I clicked on your CoDWaW server :P
Concerning your issue, I cannot find the connection log for 42106515b5ade37ff33f4f03294b564b.
I suspect streaming was lost, then the guy joined, then streaming kicked back up, but as Enforce Bans only applies during the connection process, once the guy was connected to your server he was able to stay.
I will need your PB server logs to confirm that.