If I may be so bold I'd like to make an observation and a suggestion.
In the real world, employees generally have reviews and warnings before dismissal. I understand that moderating a forum is a bit different, but if someone is not doing things the way you feel that they should, would it not be better to sit down with them and discuss where they are going wrong? Then they have a chance to try and avoid these issues and improve on their work. This would also cover you somewhat in that if they person just continues to act as they were, or indeed gets worse, you can feel safe in the knowledge that you gave them an opportunity to improve and that its really their own fault when you have to show them the door. Setting aside a person doing things based out of personal grudges or malice, people do make mistakes, especially someone trying their hand at something for the first time. It would be a real shame for someone to be removed from a post purely due to lack of guidance from more senior people.
Note: you refers to mods in general, not one specific individual.
Also, this is just something that seems to be the case from what has been presented here. If Fenrir (in this instance) had been given a warning or review, then Iapologise for sticking my oar in, but it has not been mentioned in the thread by anyone. I'm also not saying that Fenrir's dismissal was right or wrong, merely pointing out the seeming lack of any system of review or warning.