Broken rails form helper code

gistfile1.txt

Controller:

    @estimate = Hashie::Mash.new({
                      :same_address => 1,
                      :cc_number => nil,
                      :shipping_address => Hashie::Mash.new,
                      :billing_address => Hashie::Mash.new
                      })

View: 

<%= form_for @estimate, :as => :estimate, :action => "post", :url => "/orders" do |f| %>
  <%= f.check_box :same_address,{ :disabled => "disabled" } %>
<% end %>


result:
<input name="estimate[same_address]" type="hidden" value="1">
<input checked="checked" disabled="disabled" id="estimate_same_address" name="estimate[same_address]" type="checkbox" value="1">

This works, but it seems like the helpers should be doing this:
<%= hidden_field_tag 'estimate[same_address]', '0' %>
<%= check_box_tag 'estimate[same_address]', "1", @estimate[:same_address].to_s == "1", :disabled => "disabled" %>