As an Ibis clan member I see it like this.... All Clan here at ibis started as players and admins ourselves.
We know that admins (especially friends) are going to play around with each other from time to time (all in good fun).
If I'm in a server and know you... and you slap me around at the end of a match I'm not going to ban you.
That being said... lets say hypothetically your playing with another admin (who we will just call bob) you use admin powers jokingly on this person for several rounds one night and its all in good fun.
Now the next night you have a falling out with "bob" and hes really pissed at you. He was demoing the night before and posts those demos claiming he was not alright with your actions.
Now all Zero and Clan will have to go by is the demos. As stated by the rules you did abuse by using powers on a fellow admin and action would be taken.
I give you props for coming in and asking for clarification... the bottom line is that the rule states to never use admin powers on a fellow admin.
Zero is not going to check the logs every night to make sure no horse playing occurred.... but anytime you use your admin powers on another admin regardless of the reason you do so with some element of risk.