counterpoint.rb

class Counterpoint < ActiveRecord::Base
  belongs_to :owner, :class_name => "User"
  validate :ensure_owned_by_journalist

  def self.creatable?
    return false unless user_from_session
    return false if user_from_session.company_representative?
    return true
  end

  private

  def self.user_from_session
    UserSession.find && UserSession.find.user
  rescue Authlogic::Session::Activation::NotActivatedError
    nil
  end

  def ensure_owned_by_journalist
    errors.add_to_base("You must be a journalist to create a counterpoint.") unless Counterpoint.creatable?
  end
end

view.rb

    - if Counterpoint.creatable?
      = link_to "Add counterpoint", new_note_counterpoint_path(note), :class => "new_note_counterpoint_link"