I'm developing a plugin that uses GET ?x=y on the homepage to trigger a data download (JSON text). Despite setting the "no cache on GET pages" option, I still get the "broken" message as a comment when I print JSON data. It seems to be breaking the json decoding.
The action itself is triggered in the init hook and terminated with
header('Content-Type: application/json'); echo $JSON; exit;
but the comment still gets in there. Suggestions?