This reply just shows how simple-minded you can be at times, my dear plastic friend.
Sometimes, new information comes to light in other threads that clarify a situation - - such as perhaps if an infraction was issued for "personal attack" but then we discover that there was sufficient provocation to lead us to feel that the personal "attack" was not as egregious as it may have appeared upon first reading of the post.
As stoked mentioned, sometimes this comes about because the "infractee" provides good evidence to explain the situation, and sometimes just because another mod weighs in on the discussion with additional information.