Making mistakes is one thing. Intentionally breaking tribunal regulations and, likely, your character's role is something else entirely. Personally I only know of one instance where Oblain did something questionable, but others seem to be basing their judgements of Oblain on experiences of their own. That suggests, though doesn't "prove", that there may have been a good deal of "mistake-making" going on over the course of Oblain's life. Or it could just mean people are bitter because they broke the law and were caused to suffer for it.