Events from pulldown-cmark:

"<!e -hhl" -> [
  Start(Paragraph)
    Text(Boxed("<!e -hhl"))
  End(Paragraph)
]

Events from commonmark.js:

"<!e -hhl" -> [
  Html(Boxed("<!e -hhl"))
]

XML from commonmark.js:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE document SYSTEM "CommonMark.dtd">
<document xmlns="http://commonmark.org/xml/1.0">
  <html_block>&lt;!e -hhl</html_block>
</document>

This looks like start condition 4 in the specification.

I found this by testing against revision 20b52e5 of https://github.com/commonmark/commonmark.js/ — I get the same result as pulldown-cmark when I test against the code in the dingus.