When a code-block starts with a period, ROFF MS interpreted this as a command rather than a part of the code-block. The solution is to escape the periods.
[ { "endline": 207, "file": "src/Text/Pandoc/Writers/Ms.hs", "function": "blockToMs", "module": "Text.Pandoc.Writers.Ms", "startline": 207 } ]
[ { "endline": 209, "file": "src/Text/Pandoc/Writers/Ms.hs", "function": "blockToMs", "module": "Text.Pandoc.Writers.Ms", "startline": 207 } ]