Controls that read simpleContent instance data

We have some rules:


A control that reads simpleContent 
<https://www.w3.org/community/xformsusers/wiki/XForms_2.0/submit#def-simpleContent>  
instance data does so according to the kind of node it is bound to:
The root node: an xforms-binding-error is dispatched to the control.
Element nodes: If element child nodes are present, then an 
xforms-binding-error is dispatched to the control. Otherwise, the 
string-value of the node is used.


However, if I have


<instance>
    <data xmlns="">
       <time><h>12</h><m>30</m><s>00</s></time>
    </data>
</instance>
...
<output ref="time"/>


I would expect to see "123000".


Steven