Prevent Org from escaping latex results

During export, Org generates this:

\begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,
semithick]

\node[initial,state]   (A)              \{\$q$_{\text{0}}$\$\};
\node[state]           (B) [right of=A] \{\$q$_{\text{1}}$\$\};
\node[state]           (C) [right of=B] \{\$q$_{\text{2}}$\$\};
\node[accepting,state] (D) [below of=A] \{\$q$_{\text{3}}$\$\};
\node[accepting,state] (E) [below of=C] \{\$q$_{\text{4}}$\$\};

\path (A) edge [loop above] node \{\$b\$\} (A)
edge              node \{\$a\$\} (B)
(B) edge              node \{\$a\$\} (C)
edge              node \{\$a\$\} (D)
edge              node \{\$b\$\} (E)
(C) edge              node \{\$a\$\} (B);
\end{tikzpicture}


from this:

#+HEADER: :exports results
#+HEADER: :results (by-backend (pdf "latex") (t "raw"))
#+BEGIN_SRC latex
\begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,
semithick]

\node[initial,state]   (A)              {$q_0$};
\node[state]           (B) [right of=A] {$q_1$};
\node[state]           (C) [right of=B] {$q_2$};
\node[accepting,state] (D) [below of=A] {$q_3$};
\node[accepting,state] (E) [below of=C] {$q_4$};

\path (A) edge [loop above] node {$b$} (A)
edge              node {$a$} (B)
(B) edge              node {$a$} (C)
edge              node {$a$} (D)
edge              node {$b$} (E)
(C) edge              node {$a$} (B);
\end{tikzpicture}
#+END_SRC


Where by-backend looks like this:

(defmacro by-backend (&rest body)
(cl-case (when (boundp 'backend)
(org-export-backend-name backend))
,@body))
`

This behavior is present in Org version 8.2.10, but it didn't happen on my laptop with potentially different version, which I don't remember.

How to prevent it from escaping the results?