If you post a log that shows you getting ganged, without commentary, that's not really character assassination since many people are okay with ganging, especially in the context of a raid situation. In other words, it won't necessarily cause a reader to view the ganging characters negatively.

If you post a log that shows something happening to you that is almost categorically condemned (e.g. betrayal by a groupmate, gear sacrificing) then it would probably be considered assassination even without commentary, since the log itself provides enough information to cause most readers to view the character negatively.

If you post a comment about a character that, while being negative, provides no useful information about them (e.g. "Daevryn is a real man-whore") then it's usually not considered assassination, because some random person's non-specific opinion isn't likely to negatively influence someone towards that character.

There's also the matter of intent. If you post a log that has no interesting content, but does show some (arguably) negative behavior, then it is reasonable to assume it was posted purely to defame the characters shown. Such a log will most likely be removed. If, however, you post a log that has lots of interesting content and some incidental negative behavior, and you don't draw attention to the negative stuff, then it may be left up, since it's not reasonable to assume that the intent in posting the log was purely to defame the characters shown.

I should have gone to law school.