In the documentation for org-format-latex-options,
for the key :matchers, the documentation lists valid members.  The last
valid member is shown as
             "\ ["    find math expressions surrounded by \ [...\]

(backslash space left-bracket).  The space is superfluous.  Note that
there are two places where this needs to be fixed.

Emacs  : GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601)
 of 2013-03-17 on MARVIN
Package: Org-mode version 8.2.5 (release_8.2.5-417-g455fbc @
c:/users/977315/documents/.emacs.d/elisp/org/)