The burden of proof shall be upon any acusers, all knights of the guild being presumed honour bound to tell the truth.
Given the gravity of such accusations; typicialy a 2/3 majiority of the guilds council in that game would have to decide to expel any guild member found to be guilty of either above violation of the code of conduct. In such instances votes of abstention should be counted as "no" votes. For punishments of a lesser nature it should fall the the GM in that game as to how best deal with the situation. As always the guild in any game is free to adopt a more restricive policy in such matters as a part of their specific "By Laws"