I think the arbitrator took the right decision based on my limited knowledge of the rules.
Thinking more about it, nvm about that.
Some of you are misunderstanding the concept of "innocent until proven guilty". Proof of guilt can have multiple forms; in this case, what we all saw on TV or the videos showing different angles of the act can certainly be considered proof of intent. Of course, whether what is believed to be evidence is actually such should be challenge-able.
If the situation is seen from these optics, the arbitrator is as moon would call it a "moron". Whether Wideman's guilty or not, having a clean resume doesn't refute the validity of the evidences. Anything else would suggest undisciplined people don't have a first infraction of rules.