Find child where parent IS NOT a certain element

I'd like to find an empty organisation element where it is not the immediate child of a parentProblem element.

Like so..

select * from Audit.PatientAudit pa
where pa.Befor开发者_Python百科eXml.exist('//*:organisation[not(../*:parentProblem)]') = 1

But it doesn't seem to work, any ideas?

declare @T table(BeforeXml xml)

insert into @T values
('<root>
    <parentProblem>
      <organisation/>
    </parentProblem>
  </root>'), 
('<root>
    <anotherProblem>
      <organisation/>
    </anotherProblem>
  </root>'),
('<root>
    <anotherProblem>
      <organisation ID="1"/>
    </anotherProblem>
  </root>') 

select *
from @T pa
where pa.BeforeXml.exist('//organisation[local-name(..)!="parentProblem" and count(@*)=0]') = 1