Why does builtin 'test' differ from /usr/bin/test

["Com MN PG P E B Consultant 3" <mn-pg-p-e-b-consultant-3.com@xxxxxxxxxxx>]

From the zsh manpages:

  "test [ arg ... ]
       [ [ arg ... ] ]
              Like the system version of test.  Added for  compatibility;"...

But in zsh, the following two commands yield different results:

  test -a = '-?' -o -a = '?' && echo true           # true
  command test -a = '-?' -o -a = '?' && echo true   # not true

Why is the first (builtin) test true?	

Ronald
-- 
Ronald Otto Valentin Fischer
External Consultant at NGTA Operation
Siemens Networks Gmbh &Co. KG  http://www.siemens.com/networks 
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