After seeing what happened to calc, this needs to be addressed.
It should not easily possible to accidentally give leadership (or even co-leadership) to the wrong player. Right now, when you want to change leadership, every single member will appear in the list, and it can easily happen that you give the leadership to the wrong player. Malicious players could even change their names to something similar to your leaders name to try to have this happen.
My suggestion: Create a list of 'committee' members, so that you can only change leadership and co-leadership to these people. This list can only be edited by the current leader.
In our faction, we have a group of players with their leadership and co-leadership constantly rotating to make sure all timezones are covered and during warring times, we hand over the leadership multiple times a day. There needs to be additional safeguards in place to avoid yourself losing your whole faction with one misclick.
EDIT: It seems that ghosty may not have accidentally given it to the wrong player, but in any case, this is something that can happen and it will only be a matter of time before it happens to a major faction.