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>The list of problems you provided only occur with inorganic oxalic acid,
>which is present only after cooking leafy greens.  Raw leafy greens
>contain organic oxalic acid and are not a problem.  In it's organic
>(raw) state, oxalic acid helps the body assimilate calcium.

I have tendancy to believe that ! but what make you so sure?
My experience with oxalic acid rich vegetables, is that somedays the
taste is very good, and sweet and when i ate enough (variable at
different time) the taste become very dry in the mouth and kind of
acrid, not pleasant ( when eaten without seasonning and by itself).
So my take on that is that when a certain state of metabolism ask for
the specific nutrients present in oxalic acid rich vegetables, we have
in our saliva or and digestives juice something that inhibit,
conteract
the observed (in scientific studies) EFFECT of oxalic acid ...
This seems to be the case for any potential toxins poisons present in
food , are not there to stop the predation from animals but to animals
stop eating a particular plant when they feel this change in taste in
their mouth.
Because the scientific studies allways assume that there is inherent
qualities in the object observed , they failed to take in accompt the
subjective reality of the object partner  in that relationship betwen
the two. Oxalic acid don't  have inherent quality , it have thoses
quality in a specific relationship and other qualities in an other
one.
A stick can help you to walk or to be beaten with, depend of your
relationship with it at the moment.
jean-claude