In the beginning I was going to deny this, mostly because it seemed like a comedy, it seems like you guys didn't work well fulfilling the details of what has exactly happened to DiE until now and as Fisu said, if he can cheat, he can fill a simple form.
So my final decision is Your brother will remain banned for 3 more weeks, which is 25th of December. Any attempt from him to join the servers will get him listed again as banevader and this request will be denied.
Last but not least, when he gets unbanned, Any further serious rule-break from your brother will get you both in trouble. Keep this in mind as such chances are not given daily.
For any objections feel free to PM me.
Locked.
Edit: UNBANNED
Consider this your last chance and don't spoil it.