PageLabelNewIndex is wrong

Consider the following document: document.pdf

It is a simple LaTeX Beamer presentation, here is the source:

\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usetheme{metropolis}
\begin{document}

\begin{frame}
    \frametitle{Foo}
    \begin{enumerate}[<+->]
        \item One
        \item Two
    \end{enumerate}
\end{frame}

\begin{frame}
    \frametitle{Bar}
\end{frame}
\end{document}

So the document has three pages. The first two are labelled as page 1 (since the two items are uncovered one after another) and the third page is labelled as page 2.

pdftk document.pdf dump_data gives wrong page label information.

Result from pdftk port to java 3.0.8 (incorrect):

PageLabelBegin
PageLabelNewIndex: 01
PageLabelStart: 1
PageLabelPrefix: 1
PageLabelNumStyle: NoNumber
PageLabelBegin
PageLabelNewIndex: 21
PageLabelStart: 1
PageLabelPrefix: 2
PageLabelNumStyle: NoNumber

Result from pdftk 2.02 (correct):

PageLabelBegin
PageLabelNewIndex: 1
PageLabelStart: 1
PageLabelPrefix: 1
PageLabelNumStyle: NoNumber
PageLabelBegin
PageLabelNewIndex: 3
PageLabelStart: 1
PageLabelPrefix: 2
PageLabelNumStyle: NoNumber