Comments cannot be expanded unless logged in

Steps to reproduce:
1. Make sure you are logged out from jira.atlassian.com
2. Go to https://jira.atlassian.com/browse/JRA-35519
3. Click on the collapsed comments to expand them

Actual result:
Collapsed comments are showing Loading...

Expected result:
Collapsed comments are expanded shortly after having displayed Loading...

Workaround:
Login into jira.atlassian.com

Note: affected version is the one which jira.atlassian.com used at 10/21/2015 12PM (UTC) — assuming this is 7.0.0-OD-07