Perhaps the Wiki entry about place holders should be updated to make it clear that elections are binding. Eduardo is a long term player, if he was unaware of the infraction then surely others would be as well.
The rule says:
Nobles holding placeholder positions are prohibited. It is not acceptable for Keplerina to hold a position for Kepler and step down when Kepler is able to take the position again. This applies for all positions.It does not mention elections, and it's fine that way. It covers all cases.
