It seems that trying to use a simple tikz figure with math doesn't work out nicely.
A very simple example is:

\documentclass{article}
\usepackage{amsmath}
\def\pgfsysdriver{pgfsys-tex4ht.def}
\usepackage{tikz}
\begin{document}
Before
\begin{tikzpicture}
\draw[->] (0,0) -- (1,0);
\end{tikzpicture}
After
\end{document}

Compiled with
mk4ht htlatex test.tex
the <p> tag isn't closed (but a browser will probably display it correctly regardless).

Compiled with
mk4ht mzlatex test.tex
the <p> tag is closed inside the test-1.svg figure, breaking both the main test.xml document, as well as the figure.
The first part inside the svg document is:
<g transform="translate(0, 0.2 ) scale(1,-1) translate(0,0.2 )">
</p>