In writers/latex2e/__init__.py identity used instead equality. The result of this operation is implementation detail. As proposed on http://comments.gmane.org/gmane.comp.python.ideas/16547 such code even can be syntax error in future Python version.
Thanks for the report and patch. However,
the patched function (visit_admonition) was changed several releases ago and
does no longer contain this if clause.
Several other occurences of incorrect identity tests were fixed some time ago.
Interestingly, the patch is to "revision 88981" while Docutils SVN is at revision 7536.