Seems like the markdown editor is messing with arrays of arrays in code snippets.
Look at this answer from Mike Bostock:
(b[1][0] - b[0][0] and b[1][1] - b[0][1])
Was changed to:
(b[1][0] - b[0][0] and b[1][5] - b[0][6])
Weird and sometimes embarrassing for the volunteer.