If your FC leader was pulled in game from an instance to the jail he violated ToS and SE will disclose what was violated and what the circumstances are. What they wont and will not do is explain why it is a violation. Its not a GMs job to hand hold at that point.

This is how SE opperates. Your FC leader will recieve an email with further information if its a ban, a means of appeal, and other information.

To avoid bans be decent. And dont violate the ToS.