Accepted.
After reviewing the appeal, I'm accepting it as it appears there was no genuine intent to break the rules in this situation.
However, based on the clips provided, no members of the NSB pointed their weapons or attempted to restrain Warsteiner.
Because of that, your decision to open fire was not the appropriate escalation. The correct response would have been to wait until the NSB either aimed their weapons, began firing or tied up Warsteiner.
Had that occured, your reaction would have been more justifiable.
The main issue here is a failure to properly escalate the situation.
For next time make sure to follow the proper escalation procedures in the future to avoid similar incidents.
Note: While the appeal has been accepted, this ban will remain on your record.