Demoting 3 admins does seem rather dramatic, also from my experience the admins who were demoted were capable people.
I really hope there was a good reason for the demotions, cause all of this seems rather more personal than some genuine investigation.
If it was because of an investigation, I hope the time the people in question spend adminning on the server, the experience and their side of the story was also taken in consideration.
I gues the ethical rule "Admins are human and can also make mistakes" applies to this as well.
To the people who were demoted, I do find it rather childish that you took this to the forums and not tried to solve this privately with the owner staff.
Screaming and claiming that Luke does "admin abuse" will not help this situation any further and it would be better if you discussed this in a rather more rational way instead of all just grouping up against Luke.