There is no need for keep-alive for a single HEAD request. Why use HTTP/1.1?

   cat << eof |nc -vv nautil.us 80
   HEAD / HTTP/1.0^M
   Host: nautil.us^M
   User-Agent: curl/7.47.0^M
   Accept: */*^M
   Connection: close^M
   ^M
   eof

Anyway, it looks like they fixed the problem or I was mistaken.

I will need to find another example.

Meanwhile looking on stackexchange one can still see people running websites asking whether to block or "turn off" HEAD as recently as last year.

If a user expects every website to respond properly to a HEAD request, then the user might be occasionally "surprised". This is because not every person running a website understands or agrees how HEAD can be useful. Sadly, GET is the only method that a user can expect to work on across all websites.