hyperref links to first subcaptionref with memoir

Question

This is more of a bug report than a question.

When using memoir's subcaptions (not the subcaption package) and links with the hyperref package, references to subfigures always point to the first instance of that label. Here's a minimal example:

\documentclass{memoir}
\newsubfloat{figure}
\usepackage[demo]{graphicx}
\usepackage{hyperref}
\begin{document}
\begin{figure}
  \subbottom[foo\label{foo}]{\includegraphics{figure1}}
  \subbottom[bar\label{bar}]{\includegraphics{figure2}}
  \caption{\subcaptionref{foo} foo and \subcaptionref{bar} bar.}
\end{figure}
\begin{figure}
  \subbottom[qux\label{qux}]{\includegraphics{figure3}}
  \subbottom[baz\label{baz}]{\includegraphics{figure4}}
  \caption{\subcaptionref{qux} qux and \subcaptionref{baz} baz.}
\end{figure}
\end{document}

The subcaptionref on the second figure ((a) qux and (b) baz) will link to the sub figures with the same labels on the first figure ((a) foo and (b) bar). Here's someone else on the internet with the same problem.

I've found that I can work around this by declaring the sub figures after loading the hyperref package, i.e.:

\usepackage{hyperref}
\newsubfloat{figure} % this line was moved to after \usepackage{hyperref}

But I would guess that this is something that should be fixed on hyperref or memoir (or documented in one of them).