While battling the bank holiday traffic on my way home this evening I realised
why looking at the job page was causing lots of 403 errors in the Chrome
console (a spike which was reflected on the Graphite screen).
There is a separate `.json` endpoint for getting updates to a job. This enpoint
did not have the `admin=True` option set in its permissions decorator. So when
viewing a service as a platform admin you could see the page, but not receive
any AJAX-powered updates to it.