Try $A=\left(\begin{smallmatrix}0&1\\\0&0\end{smallmatrix}\right)$, $B=\left(\begin{smallmatrix}1&0\\\0&0\end{smallmatrix}\right)$, $Z=I$.
Try $A=\left(\begin{smallmatrix}0&1\\\0&0\end{smallmatrix}\right)$, $B=\left(\begin{smallmatrix}1&0\\\0&0\end{smallmatrix}\right)$, $Z=I$.