Invalid connection not picked up?

[MichaelClerx]

<?xml version="1.0" encoding="UTF-8"?>
<!-- CellML Test Suite. https://github.com/MichaelClerx/cellml-validation -->
<!-- CellML 1.0, 3.4.6.4: Parent-child relationships are defined by
                          the parent's private interface, and
                          the child's public interface. -->
<model name="map_variables_hidden_cousins_3"
       xmlns="http://www.cellml.org/cellml/1.0#">
  <component name="A" /> <!-- Parent of AA -->
  <component name="AA"> <!-- Child -->
    <variable name="a" units="newton" public_interface="out" initial_value="1" />
  </component>
  <component name="B" /> <!-- Parent of BB -->
  <component name="BB"> <!-- Hidden from AA -->
    <variable name="a" units="newton" private_interface="in" />
  </component>
  <group>
    <relationship_ref relationship="encapsulation" />
    <component_ref component="A">
      <component_ref component="AA" />
    </component_ref>
  </group>
  <group>
    <relationship_ref relationship="encapsulation" />
    <component_ref component="B">
      <component_ref component="BB" />
    </component_ref>
  </group>
  <connection>
    <map_components component_1="AA" component_2="BB" />
    <map_variables variable_1="a" variable_2="a" />
  </connection>
</model>

Cellmlmanip reads this file without complaining

[jonc125]

And links the variables?