While it's true that Michael generates lots of merge commits, if you click the link in LWN article to Andreas Cadhalpun's mail [1], then you can read that following commands were used to generate statisticts:

  Libav:
  $ git shortlog -ns --no-merges v11..HEAD | head -n15
  FFmpeg:
  $ git shortlog -ns --no-merges n2.4..HEAD | head -n15

  [1] https://lwn.net/Articles/650830/