Why doesn't it handle false in a callback in AA?

Question

Ruby on Rails

Droughty, Droughty, good afternoon.
There is ruby ​​2.1.4, rails 5, ActiveAdmin 2.0.0
ActiveAdmin has a callback:

ActiveAdmin.register Post do
  
  before_save do |post|
    post.errors.add :base, "You can't post this shit!"
    false
  end

end

In theory, an error should be added to errors and the creation of the record should be shortened.
In fact, we have the following - "You can't post this shit!" is added to errors, but the creation of the record still occurs.
Good people, where to dig, so as not to make this validation into the model?

Answer 1

Rails 5 fixed this and now you can't abort the save by returning false, but you can through
throw(:abort)