Why Acidurine99 was banned?

Acideurine99 was the 9th player to enter the Modded Minecraft Malaysia's server. He made his debut appearance on the 5th episode, titled Raid N' Grief and his last episode was on the 6th, titled The Art of the Linking Book. 

He was in the server for less than a week. The reason he was banned because a few of the server's players discovered most of their mining stuff went missing and they suspected him for such treachery. He also was found many times mining underneath other players's houses. Because of many players reported this to the server's admin, he was kicked n banned from entering the server. 

Did he really did it? None of the players were 100% sure...