Context consuming actions

We have been assuming up to now that if an action consumes the context
node, then any subsequent action requiring an XPath evaluation should
fail with an exception.
We've been using binding exception as the most reasonable exception,
but because this exact case is not called out in the spec, it seems 
reasonable
to ask the community about it...

How are other XForms implementers handling this case? 

To be specific, suppose you have an action sequence that 
performs a delete action followed by a setvalue.  However,
let the delete destroy a node that either is or is an ancestor of
the context node for the action sequence.

What happens when the setvalue runs?

<trigger ref="/some/node">
   <label>Don't press me</label>
   <action ev:event="DOMActivate">
         <delete nodeset="." at="1"/>
         <setvalue ref="." value=" 'oops' "/>
   </action>
</trigger>

Thanks,
John M. Boyer, Ph.D.
Senior Product Architect/Research Scientist
Co-Chair, W3C XForms Working Group
Workplace, Portal and Collaboration Software
IBM Victoria Software Lab
E-Mail: boyerj@ca.ibm.com  http://www.ibm.com/software/

Blog: http://www.ibm.com/developerworks/blogs/boyer/index.jsp