Upon further investigation, it sounds like my son may have played the game accidentally using our Forge loader instead of vanilla minecraft, which would be a very understandable reason for a ban. If this is indeed, the case, my apologies. I never expressed to him the importance of loading up vanilla minecraft only. He was not trying to gain an unfair advantage. I'm very sorry if this caused any problems.
Please consider unbanning us. I have taught him the importance of not using mods on a server unless it's an approved one.
Thanks,
Phlamix