Look the punishment was an overreaction, but we can't keep trying to justify what the campaign did. They botched their response so horribly, it almost made the overreaction look reasonable.
By the campaign do you mean the 1 staffer who was immediately fired?
As others have said it was the National Data Director, so saying 1 staffer is misleading. I'm not saying Bernie was personally involved, I don't think he was, but something went wrong, and it doesn't do anybody any good to keep trying to justify that.